Update set backout is not possible Issue The message "This version will not be backed out because the system has decided that this it is not safe to do so. This is a system record and there is in previous version to back out to. " is displayed while trying to Backout an update set .ReleaseAllCauseThe customer must have the application installed both via application Repo and also via update set which is something that we do not support. ResolutionCustomer can either use update sets or application repository but can never use both at the same time. The update set should be backed out and fix forward would be the resolution.