Issue with re-versioning Rise and storyline 360 (scrom 1.2) in cornerstone!!!

Hi , I have a client who purchased one of our courses developed with Rise. After few weeks we sent to the client a new version with few amendments on some wording. The client notified us that they were unable to replace the previous scorm file because of a strange error about the manifest structure. I did an analysis of the file and I spot that the identifier was the unique element who changed in that file. Can this detail be the cause? I am in contact with the client but they are not really supportive...