Users get this when choosing "Mark Forum A Read". Maybe other dialog boxed too?

5.0

Pretty generic template either than logo and color changes.

M

If you have a modified language pack in ACP -> Customization -> Languages. Please create a new language pack and see if that resolves your issue.

Stock as can be.

No modified language pack.

I migrated to 5.0 a few hrs ago.

Never touched the languages.

Yet it says "customized". Now what?

Unfortunately, you do indeed have a modified language pack

I have created a new one for you and set that as your default language pack. You may wish to review any custom language strings and update them.

Checking your community, it looks to have resolved the issue:

Got it.

thanks