Seen and Reported issues of users not being able to paste graphics into a posting on a Forum.

To confirm, you've checked Pencil > Administration > Moderation > Files? I would next check Pencil > Administration > Applications > [The Application where the issue is happening] > [File Settings]. Next I would check the Settings at the Group where this is happening. 

Thanks. Yes, I've checked overall administration. That allows a massive list of file types (the default, I suspect), but we're only using forums at present, so I've not worried. Obviously the relevant image types are included.

I cut down applications - forums to the attachment extensions gif, jpeg, jpg, png, svg some time ago, but again that should still allow the ones we are talking about.

I don't see any relevant settings at group level - unless I've missed something. Bit of a wheels within wheels effect with all these levels - I can see why they are needed, but would be nice to link them a bit so that you could see the net effect!

I've now heard from support, who are also looking at this.