This plugin seems to be broken on my sites since a few weeks back, which is a shame since I really like its functionality compared to competing ToC plugins.

Whenever I try to add ToC to a post, the post cannot be published or saved.

I get a red error on top of page when I try to save draft (“Save failed”) + am taken to a new page saying “Your website has encountered a critical error, check your email for instructions” (there is no email sent) if I try to preview or publish the post.

After this has happened I cannot edit the post in question anymore at all, which is very problematic as you can imagine.

Similarly I cannot update posts that already have the ToC in them, which is even more problematic.

I’ve tried it on two different sites, same result.

Any ideas what’s going on here?

I’m using the latest version of Twenty Twenty One theme (1.6) and WordPress (6.0.2).