When you attempt to mass parts in the catalog it only takes 1 part fail the entire job. This is painful. Take the following Example.
I have 100 parts are with the manufacturer name of Crestron. I need to change them to Crestron Electronics. I highlight the 100 parts and attempt to mass update. 1 Part in the list already exists in the catalog so it would create a duplicate part. The mass update fails at this point.
The mass update should complete for all parts that can be changed and then a pop up listing those that would create a duplicate. This way I am left with an easy list of items to correct.