10001381 
Message
Negative withholding tax not permitted; manually create a reverse journal entry
Diagnosis
You have opened the Journal Entry window and have displayed a journal entry involving withholding tax. The Automatic Tax and Manage WTax checkboxes are selected and are not editable. You have tried to select the Reverse checkbox.
However, reversing this transaction would create a negative amount for withholding tax, which is not allowed.
Note
The reversed transaction format is determined by the setting in the Company Details window. In this case, the Use Negative Amount for Reverse Transaction checkbox is selected, so the amounts in a reversed transaction appear on the same sides as in the original transaction, but with a minus sign.
Procedure
In the Journal Entry window, recreate the journal entry. Make sure that the same amounts appear on opposite sides to the original journal entry.