I perform the back up function of my software weekly to an external hard drive and the C drive of my server weekly. After backing the software up on the external drive, I tried to perform the back up on my C drive. The following error was displayed:

"Password not enabled for this module"
I restarted the sysrtem and reentered my password for the back up and it worked.
This is the second time that I have received this error (not consecutively though).
Any idea why it happens?