1) This message usually means you are trying to use a .backup file from a software version of Webwasher, not the appliance version. Is this true? This should not be a problem in that the IP address settings of the appliance are only used for documentation of the settings.
2) This is usually due to extended list or other lists having invalid entries on the original system. Try unchecking one of the options on the right and saving again. If it is finally able to save, then list you have unchecked has bad data in it.
If you cannot get past the error in this way, please email me the .backup file to my McAfee address and I will look at it to see precisely where the error is occuring.
I've follow yours recommandations and all is OK now.