@SSastry (WMF): I have no idea what the minimum requirement for MediaWiki/VisualEditor is with this release. Is it safe to use it with MW 1.31 LTS?
Topic on Talk:Parsoid/Releases
I am pretty sure now that this is breaking for MW 1.31 LTS. It would have been nice to know this in advance. Probably the HTML 2.1 version was meant to convey just this info.
I added a note about the incompatibility. I guess this is ok.
Thanks for catching this and flagging it on the page. We didn't test this with older versions (MW 1.31) but in retrospect, should have, and flagged this. Anyway, this is the last release and going forward, this version issue will not ever arise since the appropriate Parsoid version will be bundled with the MW release.
Just to double-check -- switching between source and visual editing was always somewhat broken if you weren't using RESTBase to support stashing. Are you sure this is a new regression and not just a configuration issue?
In my cases RESTBase is not involved. The issue already appears if you want to discard changes done in visual editing. Usually on gets asked to confirm that the changes are lost if you switch to source editing. With 0.11.0 you do not even get that far. An error 406 is issued for the api on MW 1.31. On 1.33 everything continues to work as expected. Both wikis are configured identically and use the same parsoid service. After downgrading to 0.10.0 MW 1.31 works again.