I get error on my page blogs and topics.

But this is very strange, because I dont change (default templates on my community) and I get this error after enter on a blog or topic.

Could you add an option to restore the original theme?
I have this message but there is no practical, quick and functional way to change the theme as mentioned in the message itself.

Sorry I post on wrong section !

You would use the support section of the admin CP and select customisations to restore a default