Error when posting an invoice

Dynamics 365 Business Central/NAV User Forum
#1

We are using NAV 2009 SP1, when posting an invoice the error below pops up. What could this be caused by?

5504.12-22-2011 11-43-42 AM.png

#2

Ah it looks like the P.O. invoice had 30 units or -30 and the remaining quantity was only 25.