Trying to correct/change document which was already posted is successful, but nevertheless the program warns you about this with the following message.

For invoices issued it means that invoices issued have been already posted automatically.

For invoices received it means that invoices received have been already posted automatically.

For set-off it means that set-off template has been already psoted.

The message conveys that you need to repost the document automatically in case you are trying to correct data significant in posting (e.g. payment amount, value, etc.).

Confirm changing of the already posted document clicking and cancel it clicking .