Hi, I recently rooted my phone and accidentally deleted the system calendar. I unfortunately, had no system back up (I know this was a mistake) so the stock calendar info is completely gone. I tried to re-install the calendar.apx file to the SD for the version of android my phone is running (Kit Kat) and it failed to install. I've been reading that if I install a new flash ROM I might be able to recover a system calendar? Is that true?