Question / Problem:
We get the following error when launching any module: KdoLib: Invalid username and/or password.: Login failed for user 'sa'. (18456)
Answer / Solution:
It has been found that in some cases someone had logged into SSMS for the SQL Express database with Windows Authentication using the same account that was used to install SQL Express, and changed the SA password. When you install SQL Express, and select Mixed Mode SQL Authentication, the Windows account that is being used to perform the installation is automatically granted SysAdmin access.
To resolve the issue, contact Kofax Support and have the password changed back by logging back into SSMS for the SQL Express instance using the same account that was used for installation. If you had right-clicked and run the installation as Administrator, you should be able to do the same by right-clicking SSMS and running as Administrator.