This implies an underlying Operating System issue. Have AD account names or domains been changed ? Is the User you are attempting to create, in the same Domain as the DLO server and Administrator account ?
I would recommend that you log onto the DLO Admin Server desktop as the DLO Administrator account and which runs the DLO\SQL services, then try to create a new User again.
If that still fails, check the Event Logs as you may be getting an error logged there for similar and that may help point you to the cause.
“No mapping between account names and security IDs was done when enrolling user, changing or resetting password”. Here are possible reasons: The user name is invalid. Make sure that the name is entered correctly and the account of this user name belongs to the specified domain.
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The reason you are getting the "No mapping between account names and security IDs was done" is either because you now have an orphaned user account.
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