so as the title says, I've updated EPiServer.CMS to 11.11.3 (and as part of that .UI & .Core to version 11.19.0) and when I try to add a new block I get a blank page:
nothing showing in the console in terms of errors. Anyone else?
just tried this with a fresh alloydemo site and I'm getting the same result so I will try and raise a bug.
Please see this thread https://world.episerver.com/forum/developer-forum/Problems-and-bugs/Thread-Container/2019/4/episerver-cms-ui--11-19-1-packages-break-content-area-create-new-block-link-functionality/
A ticket has already been raised
Bug has been raised: CMS-13807
The thread you linked to Marcus has a good temporary work around to creating the blocks if you're stuck with these packages. :)
No worries - i hope it helped