This is a new one to us... We try to enter in a purchase order. Get get all of the way through the header screen to the item entry screen. Enter in a part which we do sometimes buy from the vendor in question. It then tells us that the chosen vendor is not authorized to sell us this part (or something to that effect) and will not let us enter the part. Why isn't the vendor authorized and why do we care? No one has done anything with this. We didn't even know it could do this...

Isn't there a setting for approved vendor requirement by part number, too?

Yeah, I found the setting in the system defaults menu and it was indeed changed. There is no way that anyone other than me even thought to go into such an area. (they avoid messing with things like that like vegetarians avoid cattle ranches.) I don't sleep walk and so I know it wasn't me either. That leaves just program errors and invisible animals. I'm highly doubtful of the existence of invisible animals. So... This leaves me with program errors. This latest update has been nothing but trouble.