Is the ‘Include in Qty. Available’ checkbox selected on the warehouse/location?

I am not sure i see that under any tabs.

Go to inventory > Warehouse. Click on the writeoff warhouse and check send a screenshot of the location table.

The checkbox I’m referring to is under Warehouse/location:

I’m not familiar with manufacturing so I’m not sure if that changes how this works.  sorry. 

@bnaumann 

to address “Available” - Check the Locations tab of the Warehouses Screen (IN204000) to make sure “Include in Qty. Available” is checked.  - However, SO’s only look at the warehouse level (not locations) so this is likely not the problem.

I wonder if your SO Line has Warehouse “Main” selected.”Qty on Hand” is reported as 0.0. Depending on your configuration you may need to make the Warehouse field visible using the Column Configuration on the the SO line.