Same entry in logs. The header content contains invalid characters. We've tried to add МойОфис both manually and via copy/paste so there's no possibility of adding some special symbols exept cyrillic.

МойОфис

I want to note that cyrillic symbols in Title field works properly.

Greetings .)
We've tried to add some cyrillic symbols on "Customise the "Powered By" header sent by NodeBB" field in Avanced settings. After saving - it dropped the entire forum with admin panel itself.

Got error:
[ [global:500.title]]
[ [global:500.message]]

The header content contains invalid characters.

Solved only via manual removal of this field in redis base.
Is it a bug or...?