Since this message beings with a colon, the error is coming from ABM, not from ASPluris.
This error can happen in two ways. The first is that the user may not have the correct access privileges to allow them to perform the transaction. This can be fixed by setting the correct access privileges in ABM and then refreshing the user list in ASPluris.
The second way that the error can occur is a bit more difficult to explain. ABM has a hidden “control” database as well as the main SQL database. The control database is not accessible to ASPluris. When you add or remove users in ABM, ABM tries to keep these two databases in sync. Unfortunately, this sometimes fails, and if the user is in the SQL database but not in the control database, the user will be denied permission to write transactions to ABM, and that is what this ASPluris error message is showing.
This synchronisation problem can usually be fixed by deleting the user with the problem from ABM then adding the user back in again. This should result in the ABM databases resynchronising. You can then refresh the user list in ASPluris.