Thanks everyone. I was on the phone with Line 6 support today. They were VERY helpful. Evidently when copying an existing model to Custom 2 (without Workbench), the procedure needs to be done quickly or it may "time out" thus wont save. Line 6 support also experienced this anomaly on their end while on the phone. After quickly doing the procedure, as they recommended, I was able to successfully save to Custom 2.