Wadaco - report picking part Qty assigned error

One thing is that you have set qty_picked to have Fixed Value 0 when applicable, that would mean if the part is a serial part you will auto save 0 qty which seems very strange. The purpose is to send in 1 for serial parts, not 0, check how the template configuration (=1) looks like. 

Plus you have also set qty_picked to have automatic value to Fixed, this might be fine in some scenarios but not when you are have a so called internal loop with loop start/end, then you are in a sort semi-offline mode and the things you have picked previous loop laps are not taken into account when system tries to get the automatic value. I think that might be the reason for you error since that functionality will try and fetch qty_assigned from the customer order reservations.

I would suggest to either turn off Use Automatic Value on qty_picked if you want to still use internal loop and enter the quantities manually, or you could instead use a so called subsequent loop (or configuration linking as some call it), where you remove the loop start/end and instead loop/jump the same configuration over and over, then I would guess that Use Automatic Value Fixed on qty_picked might work better since there will be a commit between each session/loop-lap