It is possible there has been a change in the User ID in Dimensions that corresponds to the Windows User Name.
To check if an update is necessary, do the following:
Ribbon style menu:
Log in to Dimensions using a user log in account that can maintain User Records.
Select System from the main menu
Select User Records
Scroll the list of users to locate the User Name in Name column that corresponds to the Windows account that the user is using to log in with
If the User Id. is incorrect, then you can update it as follows ...
Click Edit
Change the User ID value in the box at the bottom of the screen to the one listed in the error message
Click Save
Ask the user to try logging in again.
Classic/Module Menus style menu:
Log in to Dimensions using a user log in account that can maintain User Records.
Select System Control from the navigation bar
Select Users, User Records
Continue from step 4 above
If the user ID is already correct in the user list, then the log on information may just need refreshing.
To do this:
Log in to Dimensions using a user log in account that can maintain User Records.
Select System from the main menu
Select Data Utilities
Then select Synchronise Logon Data
Once complete, ask the user to try logging in again