I just recently downgraded my NC5 back to MK2, rooted, and followed @Surge1223
's method to upgrade back to NC5 with root. I am now on NC5, stock ROM. When I try to plug my phone into my computer via USB, the phone instantly crashes and reboots. Every time. I backed my entire phone up to Samsung Kies and I need to access my phone's SD card too. Is this a known issue? Did I do something wrong? I need a reply asap please if possible.