I also saw this message today when trying to run the Recompile HAL Files maintenance, when a report was running. It didn't log me out, but I had to wait until the report had finished before it let me recompile.
Hello!
You can mark it as closed as option. If document is connected with other documents you can not delete it so you will not be able to delete PO, as you will not be able to remove Goods receipt...
