I had an issue when upgrading to 1.27.1 and I was unable to edit anything or get access to admin tools. I disabled the extension and everything is working now.
Topic on Extension talk:Semantic ACL
Unfortunately I came to this page to report the same thing. Sadly since it's marked unmaintained I expect it's done. The issue seems to be similar to the issue that Extension:Lockdown had before someone patched it.
@Werdna if this extension was marked wrongly and you're still around it would be awesome if you can fix it. thanks
@Kghbln turns I mistakenly assumed Lockdown 1.27 was the problem when it was this extension (since the problem was the same as the one described in the talk page for Lockdown). btw, thanks for making the note I added to Semantic Mediawiki about Compatibility Mode (when running Cargo also) much more noticeable.
Thanks Chris for the feedback. Yeah, this extension provides just a first line against curiosity but ... Would be nice to see this come to life again.