If you are getting this message when applying the eCart server behavior or editing it there might be a problem with the cache file. Here is a link with steps for deleting this file to get past these types of errors:
Please give this a try, if it does not work for you then there might be a corruption of the configuration folder. Here are the steps you can take for that if it is the case:
Please post back and let us know if the issue persists.