Behavior:
When upgrading our DocuWare System, the DocuWare Setup requests for the DocuWare username; however, after I enter a valid username, the following error occurs,
"Could not get administrator email address" or "Getting the email with the given credentials failed."

Solution:
To alleviate this behavior, check and ensure that any extra table columns have not been added to the DWUsers table in the DWSystem database. Please refer to all the columns that are in the DWUsers table by default:

If you have any columns that are not listed here, this is not supported by product design. Please delete them, re-run DocuWare Setup, and re-enter the DocuWare username again. The email address should now populate, and the upgrade should now proceed without error.
KBA is applicable for On-premise Organizations ONLY.