When switching between Read/Edit I sometimes get Uncaught TypeError: Cannot read property 'mwTocWidget' of undefined.
I can reproduce it in production on mediawiki.org. I guess it comes from a race condition in setup/teardown of VE target activation.
- T88831: [Regression pre-wmf17] Cannot open any page with VE in Betalabs , "TypeError: Cannot read property 'setDisabled' of null" appears in the console
- T64934: VisualEditor: [Regression pre-wmf20] TOC widget doesn't tear itself down correctly, throws Cannot call method 'teardown' of undefined while trying to save a page on Betalabs
- T135387: "Uncaught TypeError: Cannot read property '0' of undefined" and VE not loading when repeatedly switching back and forth between read and edit modes