This can occur when you try to perform the carryforward after accessing a function in UltimateTax that uses the Select Directory dialog box (such as Backup/Restore or reinstall state/bank software). After you close the program and reopen it, you can perform the prior-year carryforward successfully.
Alternatively, you can insert the drive letter where the prior year of UltimateTax is installed in front of the Directory containing the path of the file.
This information applies to all years of the UltimateTax software.