Limited Support
Our team is currently on holiday, so support will be limited during this period. Response times may be slower than usual, and some inquiries may be delayed.
We appreciate your patience and understanding, and we’ll resume our usual support by the end of August.
Ok. I think your website is infected. Or some security solution works incorrect on hosting service.
Infected? With what?
Check this topic and then run your URL check at:
https://www.ssllabs.com/ssltest/index.html
And let us know ....
Also have you tried with one browser or a few ? Could be a local (your pc) issue ? Some addon on the browser ?
Google " The requested URL was rejected. If you think this is an error, please contact the webmaster.
Your support ID is: "
and try each suggestion. Definitely not wpForo related.