I am having a rebuild error on a mirrored part. This occurs on only the mirrored part that has a different configuration of the original. This occurs when taking SW 2015 parts and saving them as SW 2018 parts. I have removed the additional configurations to leave only the defaults and the mirrored part still shows the rebuild error. Rebuilding the part on any level does not fix this. These are sheet metal parts and the error only occurs on assembly levels including the mirrored part. When the part is opened, no error shows. How can I remove or fix this rebuild error without recreating the mirrored part? I will be saving older SW parts regularly and would like to save time by not having to create new mirror parts in every instance to avoid the rebuild errors.