Soon after releasing the Update Rollup 2 for System Center 2012 r2 products numerous threads start in technical forums issues related with DPM 2012 R2. Most of them are related to Tape backup & recovery.
Below thread discuss such issue scenario,
Good news is Microsoft DPM team acknowledge the issue nd quickly withdraw the update from the web site,
Recovering from the issue is quite complex and need Microsoft support in certain cases. This also remind us the thumb rule of not applying latest updates to production environment without proper study. It’s always ideal to test them in staging environment.