This is a report from someone else.
I think the steps were:
- Create article (in draft namespace) in visual mode.
- Save first edit.
- Edit source
- Switch to visual
The content was then truncated, with the following error:
VM485:574 Error: Failed to restore auto-saved session: TypeError: this.children[i].getAnnotatedHtml is not a function at VeDmSurface.ve.dm.Surface.restoreChanges (load.php?debug=false&lang=en&modules=ext.CodeMirror.lib|ext.visualEditor.core&skin=vector&version=12jvj8k:426) at VeInitMwDesktopArticleTarget.ve.init.mw.ArticleTarget.surfaceReady (<anonymous>:573:933) at VeInitMwDesktopArticleTarget.ve.init.mw.DesktopArticleTarget.surfaceReady (<anonymous>:1091:917) ve.init.mw.ArticleTarget.surfaceReady @ VM485:574