Compactlogix PLC with Devicenet Scanner

Yesterday I manually configured the scanner to make the machine run again and then later the customer removed power for only two hours. When power was applied again, the network configuration in the scanner was gone. Why would this scanner (approximately 5 years old) not retain the network congiuration after a short power loss?

What is the error message show on scaner?

The scanner module display alternates 63 and 75. 63 for the node number of ther scanner and 75 for "no communications." Keep in mind the scanner was manually configured and the machine was "running" with steady 00 in the scanner display (meaning all is normal). The customer removed power for two hours and restored power. 63 and 75 appeared before the manual software configuration and again after the power removal.

When you download the program into the scanner it is stored in Non-Volitile memory. Sanitation turns off the power to my CompactLogix every night and it is restored in the morning. Perhaps someone went online and it asked Upload/Download and they selected the wrong option?
Would not be the first time that ever happened.