iMessage Pics/Attachments Not Appearing on MBP

I am getting the below in place of photos sent and received in iMessage on my MacBook Pro. Any ideas?

I found support forum solutions from earlier MacOS versions indicating that the fix is to delete and recreate the Attachments folder within Library>Messages. In my Library>Messages, there is only 1 folder called plug-ins, and the File>New Folder option is greyed out.

I appreciate any support.