The customer has an issue in Fixed assets - "Depreciation transactions in Fixed asset XXX Book YYY for a zero amount in the reporting currency aren’t allowed when the asset’s net book value is greater than zero in the reporting currency"

we had an active BUG 747817 with same issue and raised work item for resolution for this error message.

PG team provided update as, we're unable to fix the issue now due to the magnitude of the fix, other priorities, or both. 

The customer can apply the workaround by using "Depreciation adjustment" and will get the expected results.

In future please enable this feature and permanent solution in upcoming versions to show as expected values without depreciation errors and post successfully .it will help customer to perform regular process.