If you are trying to restore a binary backup for the Avaya/Nortel Enterprise Routing Switch 5xxx series switch/stack and you are getting a "Data is for different physical ID's. Operation aborted." message, don't bother wasting time with Nortel support because after 3 hours of troubleshooting it will boil down to this - Avaya does not have a tool to convert, decompile or analyze binary backup files for the ERS switches...
The only reasons why you would be seeing such an error are:
1. You are trying to restore the binary backup to a stack where stack units (individual switches) are not in the same order as they were when the backup was taken. If this is the case - best hope that you remember what order they were in and don't worry about any new switches you have added as replacements - this check is done by MAC address of the individual units, and any new entries will be ignored. So the first thing to try is re-arranging the stack units back to its original order, filling the gaps with switches of the same type that were not previously present in the stack and then try applying the configuration file again.
2. If your farm has remained unchanged and yet you are still getting the "Data is for different physical ID's. Operation aborted." - you are in for a treat (this is what happened in our case and we have tried everything, even building a same size stack out of brand new switches and attempting to restore configuration to it, all in vain)... This means that your configuration file is corrupt (and chances are that some of the backups you have taken from this stack before are also un-usable, in our case we had to roll back almost 6 months - back to the point when something went wrong with the backup engine on the stack). Unfortunately, as I mentioned earlier, Nortel does not have any means of correcting, analyzing or decompiling the binary backup files - which is what they will tell you should you attempt to contact them for advanced troubleshooting... your only hope in this case is rolling back to older backups, one-by-one until you find a good one, or using an ASCII backup if you have it.
Hopefully this will save you a weekend wasted on troubleshooting and if you are to take one lesson out of reading this article it should be - always make ASCII backups. I know I do now - they can be read, analyzed and taken apart into pieces that can help you restore your VLANs, QoS rules and MAC address tables as needed. Just make sure to store them in a safe location - ASCII backup files contain everything in clear text, including passwords.