The query functionality in the ApiSandbox seems to be broken on Commons. Selecting action=query returns the headers "Lists, properties, Meta information" but none of the underlying functions.

Since it is still working fine on sv.wikipedia.org I'm reporting it here rather than in extensions.

To reproduce
Go to https://commons.wikimedia.org/wiki/Special:ApiSandbox
Select query

Version: wmf-deployment
Severity: normal