1. when doing a system upgrade, a lot of times the new version won't play nicely with the old version. Key example iFix, not backwards (or forwards!) compatible

1. when doing a system upgrade, a lot of times the new version won't play nicely with the old version. Key example iFix, not backwards (or forwards!) compatible. 2. sometimes addin a quick fix with a support engineer on the line is quicker than attempting a role back. You're making a lot of assumptions here, but likely what happened was a try to fix this asap and if that fails roll back scenario.