Error message trying to upload image as attachment

Just tried to upload 7kb image to show a members something here in a conversation and keep getting a red error message bar, unable to upload. It's a jpg image, and only 7kb large.

Testing to see if I can upload same image in a thread, and not a PM conversation.

 

Works in a thread, but in a conversation it throws an error message up

 

That was happening to me a while ago, I think I reported it...

 

Suppose it's something Brandon can't fix, he is running unsupported Beta 3 here.

 

Only Beta 3? RC was released last week...

 

We're on the RC
I haven't had time to check the pm attachment error mentioned above.