Supplier Return Credit errors "Object reference not set to an instance of an object"

Problem

Entering a supplier return credit results in the error "Object reference not set to an instance of an object".  The error occurs when adding an inventory item to the form against an FX creditor

Solution

The issue is due to there being no record for 'No Code' tax entry in the GST Adjustments Inwards tab in the Tax Configuration table.  Enter a 'No Code' entry against the GST Adjustments Inwards table and the supplier return credit can then be successfully created.

The issue only applies to versions 7.00.175 and earlier.