classic "Unfortunately the Process.com.android.phone Has Stopped" - with a twist

A

AC Question

After updating my Oneplus One to cyanogen 13.0 the message above was displayed. After completing the suggestions from the many threads on this isssue (clearing phone,simkit cache) I began to implement a factory reset, however when I plug my phone into the computer it says it has no files.
notes:
- really slow phone performance
- messages saying no sim card
- Constant crashing
- Constantly displaying the message "Unfortunately the Process.com.android.phone Has Stopped"