The Not Wikilambda test wiki has a few issues at the moment.
Trying to view any existing ZObject yields an error:
[be242de537c2824315e9fa88] /wiki/ZObject:Z1 Error: Call to a member function getLabel() on null Backtrace: from /data/project/notwikilambda/public_html/w/extensions/WikiLambda/includes/ZObjectContent.php(302) #0 /data/project/notwikilambda/public_html/w/includes/content/AbstractContent.php(591): MediaWiki\Extension\WikiLambda\ZObjectContent->fillParserOutput(Title, integer, ParserOptions, boolean, ParserOutput) #1 /data/project/notwikilambda/public_html/w/includes/Revision/RenderedRevision.php(263): AbstractContent->getParserOutput(Title, integer, ParserOptions, boolean) #2 /data/project/notwikilambda/public_html/w/includes/Revision/RenderedRevision.php(235): MediaWiki\Revision\RenderedRevision->getSlotParserOutputUncached(MediaWiki\Extension\WikiLambda\ZObjectContent, boolean) #3 /data/project/notwikilambda/public_html/w/includes/Revision/RevisionRenderer.php(217): MediaWiki\Revision\RenderedRevision->getSlotParserOutput(string, array) (snip)
When trying to create a new object, the list of available languages for the label is empty:
When trying to create a new language object, there is a strange error message:
⧼⧼Value 'en' for 'Z11K1' of type 'Reference(Language)' is invalid.⧽⧽
I suspect that these are all related to the migration from language codes to languages (T279114), though this is just a guess: maybe the existing objects weren’t properly converted, which is why they can’t be viewed now, and because there are no Z60 instances yet, there are no languages available for labels. I’m not sure about that last error, though, why it’s not possible to create new language instances. (Note that the error message mentions a key Z11K1 and a language code en, neither of which actually occur in the request payload.)