when trying to insert > pages i get a 404 message chrome browser
Topic on VisualEditor/Feedback
Based on the fact that you later managed to make that edit, and since I can't no longer reproduce (WFM), I believe this is an occasional problem which we are still trying to diagnose properly. Hence, thanks for reporting it.
yes encountered 3 times when editing existing article in WS
it was not happening before for me with the same process
it does lose all work, so not graceful fail