I'll add..
Seems that more is broken than just having the warnings splashed all over the place. I can't reply to other posts and it seems, maybe, the private messaging system isn't all that happy either. As such here's a link I tried PMing earlier that may help understand the situation..
From: https://community.mybb.com/post-1391544.html
Which in response to a post describing a similar situation in part says..
your hoster has changed your Webspace to PHP8
You can deactivate the display of warnings in the acp
acp --> configuration --> Server & Optimization
Seems that more is broken than just having the warnings splashed all over the place. I can't reply to other posts and it seems, maybe, the private messaging system isn't all that happy either. As such here's a link I tried PMing earlier that may help understand the situation..
From: https://community.mybb.com/post-1391544.html
Which in response to a post describing a similar situation in part says..
your hoster has changed your Webspace to PHP8
You can deactivate the display of warnings in the acp
acp --> configuration --> Server & Optimization