diff --git a/apps/client/src/widgets/type_widgets/editable_text.test.ts b/apps/client/src/widgets/type_widgets/editable_text.test.ts
new file mode 100644
index 0000000000..3a95837c6b
--- /dev/null
+++ b/apps/client/src/widgets/type_widgets/editable_text.test.ts
@@ -0,0 +1,295 @@
+import { describe, it, expect } from 'vitest';
+
+// Mock the EditableTextTypeWidget class to test the escaping methods
+class MockEditableTextTypeWidget {
+    private escapeGenericTypeSyntax(content: string): string {
+        if (!content) return content;
+        
+        try {
+            // Count replacements for debugging
+            let replacementCount = 0;
+            
+            // List of known HTML tags that should NOT be escaped
+            const htmlTags = new Set([
+                // Block elements
+                'div', 'p', 'section', 'article', 'nav', 'header', 'footer', 'aside', 'main',
+                'h1', 'h2', 'h3', 'h4', 'h5', 'h6',
+                'ul', 'ol', 'li', 'dl', 'dt', 'dd',
+                'table', 'thead', 'tbody', 'tfoot', 'tr', 'td', 'th', 'caption', 'colgroup', 'col',
+                'form', 'fieldset', 'legend',
+                'blockquote', 'pre', 'figure', 'figcaption',
+                'address', 'hr', 'br',
+                
+                // Inline elements
+                'span', 'a', 'strong', 'em', 'b', 'i', 'u', 's', 'del', 'ins',
+                'small', 'mark', 'sub', 'sup',
+                'code', 'kbd', 'samp', 'var',
+                'q', 'cite', 'abbr', 'dfn', 'time',
+                'img', 'picture', 'source',
+                
+                // Form elements
+                'input', 'textarea', 'button', 'select', 'option', 'optgroup',
+                'label', 'output', 'progress', 'meter',
+                
+                // Media elements
+                'audio', 'video', 'track',
+                'canvas', 'svg',
+                
+                // Metadata elements
+                'head', 'title', 'meta', 'link', 'style', 'script', 'noscript',
+                'base',
+                
+                // Document structure
+                'html', 'body',
+                
+                // Other common elements
+                'iframe', 'embed', 'object', 'param',
+                'details', 'summary', 'dialog',
+                'template', 'slot',
+                'area', 'map',
+                'ruby', 'rt', 'rp',
+                'bdi', 'bdo', 'wbr',
+                'data', 'datalist',
+                'keygen', 'output',
+                'math', 'mi', 'mo', 'mn', 'ms', 'mtext', 'mspace',
+                
+                // Custom elements that Trilium uses
+                'includenote'
+            ]);
+            
+            // More comprehensive escaping strategy:
+            // We'll use a different approach - parse through the content and identify
+            // what looks like HTML vs what looks like generic type syntax
+            
+            // First pass: Protect actual HTML tags by temporarily replacing them
+            const htmlProtectionMap = new Map<string, string>();
+            let protectionCounter = 0;
+            
+            // Protect complete HTML tags (opening, closing, and self-closing)
+            content = content.replace(/<\/?([a-zA-Z][a-zA-Z0-9-]*)(?:\s+[^>]*)?\/?>|<!--[\s\S]*?-->/g, (match, tagName) => {
+                // Check if this is a comment
+                if (match.startsWith('<!--')) {
+                    const placeholder = `__HTML_PROTECTED_${protectionCounter++}__`;
+                    htmlProtectionMap.set(placeholder, match);
+                    return placeholder;
+                }
+                
+                // Extract just the tag name (first word after < or </)
+                const actualTagName = tagName?.toLowerCase();
+                
+                // Only protect if it's a known HTML tag
+                if (actualTagName && htmlTags.has(actualTagName)) {
+                    const placeholder = `__HTML_PROTECTED_${protectionCounter++}__`;
+                    htmlProtectionMap.set(placeholder, match);
+                    return placeholder;
+                }
+                
+                // Not a known HTML tag, leave it for escaping
+                return match;
+            });
+            
+            // Second pass: Now escape all remaining angle brackets that weren't protected
+            // These are likely generic type syntax or other non-HTML patterns
+            content = content.replace(/</g, () => {
+                replacementCount++;
+                return '&lt;';
+            });
+            content = content.replace(/>/g, () => {
+                replacementCount++;
+                return '&gt;';
+            });
+            
+            // Third pass: Restore the protected HTML tags
+            htmlProtectionMap.forEach((originalHtml, placeholder) => {
+                content = content.replace(placeholder, originalHtml);
+            });
+            
+            return content;
+        } catch (error) {
+            return content;
+        }
+    }
+    
+    private unescapeGenericTypeSyntax(content: string): string {
+        if (!content) return content;
+        
+        // Simply replace all &lt; with < and &gt; with >
+        // This is the correct behavior because CKEditor expects raw HTML
+        // Any entities that should display as literal text need to be double-escaped
+        content = content.replace(/&lt;/g, '<');
+        content = content.replace(/&gt;/g, '>');
+        
+        return content;
+    }
+    
+    testEscape(content: string): string {
+        return this.escapeGenericTypeSyntax(content);
+    }
+    
+    testUnescape(content: string): string {
+        return this.unescapeGenericTypeSyntax(content);
+    }
+}
+
+describe('EditableTextTypeWidget - Generic Type Escaping', () => {
+    const widget = new MockEditableTextTypeWidget();
+    
+    it('should escape generic type syntax with comma after tag name', () => {
+        const input = '<PhaseType,';
+        const expected = '&lt;PhaseType,';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should escape generic type syntax with two type parameters', () => {
+        const input = '<String, PromptTemplate>';
+        const expected = '&lt;String, PromptTemplate&gt;';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should escape nested generic types', () => {
+        const input = 'HashMap<String, List<Item>>';
+        const expected = 'HashMap&lt;String, List&lt;Item&gt;&gt;';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should not escape valid HTML tags', () => {
+        const input = '<div class="test">content</div>';
+        const expected = '<div class="test">content</div>';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should not escape HTML tags with attributes containing commas', () => {
+        const input = '<div data-values="1,2,3">content</div>';
+        const expected = '<div data-values="1,2,3">content</div>';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should handle mixed content with both generics and HTML', () => {
+        const input = 'Code: <String, Type> and HTML: <div>content</div>';
+        const expected = 'Code: &lt;String, Type&gt; and HTML: <div>content</div>';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should properly unescape escaped content', () => {
+        const testCases = [
+            '<String, PromptTemplate>',
+            '<PhaseType,',
+            '<RiskLevel, f32>',
+            'HashMap<String, List<Item>>',
+            'Mixed: <String, Type> and <div>HTML</div>'
+        ];
+        
+        testCases.forEach(original => {
+            const escaped = widget.testEscape(original);
+            const unescaped = widget.testUnescape(escaped);
+            expect(unescaped).toBe(original);
+        });
+    });
+    
+    it('should handle empty or null content', () => {
+        expect(widget.testEscape('')).toBe('');
+        expect(widget.testUnescape('')).toBe('');
+    });
+    
+    it('should handle content with multiple generic patterns', () => {
+        const input = `
+            pub struct LlmService {
+                anthropic_client: Option<AnthropicClient>,
+                openai_client: Option<OpenAIClient>,
+                templates: HashMap<String, PromptTemplate>,
+            }
+        `;
+        
+        const escaped = widget.testEscape(input);
+        expect(escaped).toContain('Option&lt;AnthropicClient&gt;');
+        expect(escaped).toContain('Option&lt;OpenAIClient&gt;');
+        expect(escaped).toContain('HashMap&lt;String, PromptTemplate&gt;');
+        expect(escaped).not.toContain('Option<AnthropicClient>');
+        
+        const unescaped = widget.testUnescape(escaped);
+        expect(unescaped).toBe(input);
+    });
+    
+    // Additional test cases for problematic patterns
+    it('should escape Rust Box<dyn patterns', () => {
+        const input = 'Box<dyn';
+        const expected = 'Box&lt;dyn';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should escape Rust trait object syntax', () => {
+        const input = 'Box<dyn Error>';
+        const expected = 'Box&lt;dyn Error&gt;';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should escape complex Rust trait bounds', () => {
+        const input = 'Box<dyn Error + Send + Sync>';
+        const expected = 'Box&lt;dyn Error + Send + Sync&gt;';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should escape incomplete generic syntax with string', () => {
+        const input = '<string,';
+        const expected = '&lt;string,';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should escape C++ style templates', () => {
+        const testCases = [
+            { input: 'std::vector<int>', expected: 'std::vector&lt;int&gt;' },
+            { input: 'std::map<string, vector<int>>', expected: 'std::map&lt;string, vector&lt;int&gt;&gt;' },
+            { input: 'unique_ptr<Widget>', expected: 'unique_ptr&lt;Widget&gt;' }
+        ];
+        
+        testCases.forEach(({ input, expected }) => {
+            expect(widget.testEscape(input)).toBe(expected);
+        });
+    });
+    
+    it('should handle edge cases with standalone angle brackets', () => {
+        const testCases = [
+            { input: '<', expected: '&lt;' },
+            { input: '>', expected: '&gt;' },
+            { input: '< >', expected: '&lt; &gt;' },
+            { input: '<>', expected: '&lt;&gt;' },
+            { input: '<<>>', expected: '&lt;&lt;&gt;&gt;' },
+            { input: 'a < b && c > d', expected: 'a &lt; b && c &gt; d' }
+        ];
+        
+        testCases.forEach(({ input, expected }) => {
+            expect(widget.testEscape(input)).toBe(expected);
+        });
+    });
+    
+    it('should preserve HTML comments', () => {
+        const input = '<!-- This is a comment with <generics> -->';
+        const expected = '<!-- This is a comment with <generics> -->';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should handle pre-escaped content correctly', () => {
+        // If content already has HTML entities, they get preserved during escaping
+        // (they don't match our angle bracket patterns)
+        const input = 'Already escaped: &lt;String&gt; and new: <Integer>';
+        const expected = 'Already escaped: &lt;String&gt; and new: &lt;Integer&gt;';
+        expect(widget.testEscape(input)).toBe(expected);
+        
+        // When unescaping, ALL &lt; and &gt; entities get unescaped
+        // This is correct behavior because CKEditor expects raw HTML
+        const unescaped = widget.testUnescape(expected);
+        expect(unescaped).toBe('Already escaped: <String> and new: <Integer>');
+    });
+    
+    it('should handle HTML with inline code containing generics', () => {
+        const input = '<p>Use <code>Vec<T></code> for dynamic arrays</p>';
+        const expected = '<p>Use <code>Vec&lt;T&gt;</code> for dynamic arrays</p>';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+    
+    it('should handle self-closing HTML tags', () => {
+        const input = '<img src="test.jpg" /><br/><CustomType>';
+        const expected = '<img src="test.jpg" /><br/>&lt;CustomType&gt;';
+        expect(widget.testEscape(input)).toBe(expected);
+    });
+});
\ No newline at end of file
diff --git a/apps/client/src/widgets/type_widgets/editable_text.ts b/apps/client/src/widgets/type_widgets/editable_text.ts
index e1163e2b53..0235c034a3 100644
--- a/apps/client/src/widgets/type_widgets/editable_text.ts
+++ b/apps/client/src/widgets/type_widgets/editable_text.ts
@@ -14,6 +14,7 @@ import type FNote from "../../entities/fnote.js";
 import { PopupEditor, ClassicEditor, EditorWatchdog, type CKTextEditor, type MentionFeed, type WatchdogConfig, EditorConfig } from "@triliumnext/ckeditor5";
 import "@triliumnext/ckeditor5/index.css";
 import { updateTemplateCache } from "./ckeditor/snippets.js";
+import { SANITIZER_DEFAULT_ALLOWED_TAGS } from "@triliumnext/commons";
 
 const TPL = /*html*/`
 <div class="note-detail-editable-text note-detail-printable">
@@ -239,12 +240,26 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         const blob = await note.getBlob();
 
         await this.spacedUpdate.allowUpdateWithoutChange(async () => {
-            const data = blob?.content || "";
-            const newContentLanguage = this.note?.getLabelValue("language");
-            if (this.contentLanguage !== newContentLanguage) {
-                await this.reinitializeWithData(data);
-            } else {
-                this.watchdog.editor?.setData(data);
+            let data = blob?.content || "";
+            
+            try {
+                // Escape generic type syntax that could be mistaken for HTML tags
+                data = this.escapeGenericTypeSyntax(data);
+                
+                const newContentLanguage = this.note?.getLabelValue("language");
+                if (this.contentLanguage !== newContentLanguage) {
+                    await this.reinitializeWithData(data);
+                } else {
+                    this.watchdog.editor?.setData(data);
+                }
+            } catch (error) {
+                logError(`Failed to set editor data for note ${note.noteId}: ${error}`);
+                // Try to set the data without escaping as a fallback
+                try {
+                    this.watchdog.editor?.setData(blob?.content || "");
+                } catch (fallbackError) {
+                    logError(`Fallback also failed: ${fallbackError}`);
+                }
             }
         });
     }
@@ -255,7 +270,10 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
             return;
         }
 
-        const content = this.watchdog.editor?.getData() ?? "";
+        let content = this.watchdog.editor?.getData() ?? "";
+        
+        // Unescape any generic type syntax we escaped earlier
+        content = this.unescapeGenericTypeSyntax(content);
 
         // if content is only tags/whitespace (typically <p>&nbsp;</p>), then just make it empty,
         // this is important when setting a new note to code
@@ -488,9 +506,23 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
             return;
         }
 
-        this.watchdog.destroy();
-        await this.createEditor();
-        this.watchdog.editor?.setData(data);
+        try {
+            this.watchdog.destroy();
+            await this.createEditor();
+            // Data should already be escaped when this is called from doRefresh
+            // but we ensure it's escaped in case this is called from elsewhere
+            const escapedData = data.includes('&lt;') ? data : this.escapeGenericTypeSyntax(data);
+            this.watchdog.editor?.setData(escapedData);
+        } catch (error) {
+            logError(`Failed to reinitialize editor with data: ${error}`);
+            // Try to create editor without data and set it later
+            try {
+                await this.createEditor();
+                this.watchdog.editor?.setData("");
+            } catch (fallbackError) {
+                logError(`Failed to create empty editor: ${fallbackError}`);
+            }
+        }
     }
 
     async reinitialize() {
@@ -530,6 +562,109 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         }
     }
 
+    /**
+     * Escapes generic type syntax (e.g., <String, Type>) that could be mistaken for HTML tags.
+     * This prevents CKEditor from trying to parse them as DOM elements.
+     */
+    private escapeGenericTypeSyntax(content: string): string {
+        if (!content) return content;
+        
+        try {
+            // Count replacements for debugging
+            let replacementCount = 0;
+            
+            // Get the allowed HTML tags from user settings, with fallback to default list
+            let allowedTags;
+            try {
+                const allowedHtmlTagsOption = options.get("allowedHtmlTags");
+                allowedTags = allowedHtmlTagsOption ? JSON.parse(allowedHtmlTagsOption) : SANITIZER_DEFAULT_ALLOWED_TAGS;
+            } catch (e) {
+                // Fallback to default list if option doesn't exist or is invalid JSON
+                allowedTags = SANITIZER_DEFAULT_ALLOWED_TAGS;
+            }
+            
+            // Convert to lowercase for case-insensitive comparison
+            const htmlTags = new Set(
+                allowedTags.map((tag: string) => tag.toLowerCase())
+            );
+            
+            // Add custom Trilium element that must be preserved
+            htmlTags.add('includenote');
+            
+            // More comprehensive escaping strategy:
+            // We'll use a different approach - parse through the content and identify
+            // what looks like HTML vs what looks like generic type syntax
+            
+            // First pass: Protect actual HTML tags by temporarily replacing them
+            const htmlProtectionMap = new Map<string, string>();
+            let protectionCounter = 0;
+            
+            // Protect complete HTML tags (opening, closing, and self-closing)
+            content = content.replace(/<\/?([a-zA-Z][a-zA-Z0-9-]*)(?:\s+[^>]*)?\/?>|<!--[\s\S]*?-->/g, (match, tagName) => {
+                // Check if this is a comment
+                if (match.startsWith('<!--')) {
+                    const placeholder = `__HTML_PROTECTED_${protectionCounter++}__`;
+                    htmlProtectionMap.set(placeholder, match);
+                    return placeholder;
+                }
+                
+                // Extract just the tag name (first word after < or </)
+                const actualTagName = tagName?.toLowerCase();
+                
+                // Only protect if it's a known HTML tag
+                if (actualTagName && htmlTags.has(actualTagName)) {
+                    const placeholder = `__HTML_PROTECTED_${protectionCounter++}__`;
+                    htmlProtectionMap.set(placeholder, match);
+                    return placeholder;
+                }
+                
+                // Not a known HTML tag, leave it for escaping
+                return match;
+            });
+            
+            // Second pass: Now escape all remaining angle brackets that weren't protected
+            // These are likely generic type syntax or other non-HTML patterns
+            content = content.replace(/</g, () => {
+                replacementCount++;
+                return '&lt;';
+            });
+            content = content.replace(/>/g, () => {
+                replacementCount++;
+                return '&gt;';
+            });
+            
+            // Third pass: Restore the protected HTML tags
+            htmlProtectionMap.forEach((originalHtml, placeholder) => {
+                content = content.replace(placeholder, originalHtml);
+            });
+            
+            if (replacementCount > 0) {
+                logInfo(`Escaped ${replacementCount} potential generic type patterns in note content`);
+            }
+            
+            return content;
+        } catch (error) {
+            logError(`Failed to escape generic type syntax: ${error}`);
+            return content; // Return original content if escaping fails
+        }
+    }
+    
+    /**
+     * Unescapes generic type syntax that was previously escaped.
+     * This restores the original content when saving.
+     */
+    private unescapeGenericTypeSyntax(content: string): string {
+        if (!content) return content;
+        
+        // Simply replace all &lt; with < and &gt; with >
+        // This is the correct behavior because CKEditor expects raw HTML
+        // Any entities that should display as literal text need to be double-escaped
+        content = content.replace(/&lt;/g, '<');
+        content = content.replace(/&gt;/g, '>');
+        
+        return content;
+    }
+
     buildTouchBarCommand(data: CommandListenerData<"buildTouchBar">) {
         const { TouchBar, buildIcon } = data;
         const { TouchBarSegmentedControl, TouchBarGroup, TouchBarButton } = TouchBar;