diff --git a/web/src/components/AgentFilePreview.vue b/web/src/components/AgentFilePreview.vue
index 9da2651a..daa5fd9f 100644
--- a/web/src/components/AgentFilePreview.vue
+++ b/web/src/components/AgentFilePreview.vue
@@ -327,14 +327,16 @@ const fullscreenPreviewVisible = ref(false)
 const htmlPreviewRenderKey = ref(0)
 
 const isMarkdown = computed(() => isMarkdownPreview(props.filePath, props.file?.previewType))
-const canEdit = computed(
-  () =>
+const canEdit = computed(() => {
+  const previewType = props.file?.previewType
+  return (
     props.editable &&
     props.file?.supported !== false &&
     typeof props.file?.content === 'string' &&
-    props.file?.previewType === 'text' &&
+    (previewType === 'text' || previewType === 'markdown') &&
     (props.editAllText || EDITABLE_EXTENSIONS.has(getPreviewFileExtension(props.filePath)))
-)
+  )
+})
 const savedContent = computed(() => formatContent(props.file?.content))
 const draftChanged = computed(() => draftContent.value !== savedContent.value)
 const isHtmlFile = computed(
diff --git a/web/src/utils/markdown_preview.js b/web/src/utils/markdown_preview.js
index e048c93d..e80e829a 100644
--- a/web/src/utils/markdown_preview.js
+++ b/web/src/utils/markdown_preview.js
@@ -145,7 +145,13 @@ const ensureLanguages = async (highlighter, languages) => {
   await Promise.all(
     languages
       .filter((language) => !loaded.has(language))
-      .map((language) => highlighter.loadLanguage(language).catch(() => null))
+      .map((language) => {
+        try {
+          return highlighter.loadLanguage(language).catch(() => null)
+        } catch {
+          return null
+        }
+      })
   )
 }