Helron what was your phone doing? I too dirty flashed CM 10.2 and I started getting error messages such as no sim power off and reboot with a sim card. All I would do is power down pull out sim, put it back in and reboot. Has happened on both Stock and CM. Annoying but works. I am not sure if its the SIM or not. Is this what you were experiencing? Also flashed gapps for 4.3 and can't update some apps such as MAPs...
The first thing that I noticed was the inability to send/receive calls. Dead radio on Cm10.2. I use an app called Lte On/Off and it allows user to get into phone settings and check radio and network connections. Also, never lot 4g. Then, I switched to stock, to see if the same calling issues were present. Stock was fine until went back to Rom. Then i removed the SIM and stillhad same issue on Rom and stock. I didn't thinkitwas SIM issue. but VZ did! So, I went and picked up a new Sim card. Wouldn'tlet them see the phone, because it was rooted. LOl
Came home and put in new SIM. Still no radio signal, no network provider, nothing! Finally, after researching it to death, I found other users experiencing the same issue with CM10 Rom and many with CM10.2 upgrade.
I then decided to Ue Matt's Utility (which I love!!) and wipe the phone. So, I am on stock now, and think I may remain there until I feel the need to go back to a Rom.
Got a memo from a user who suggested Blurry Rom. Never heard of it. Maybe Ill try Liquid smooth, who knows? My fear is this: The xt912 will be losing alot of folks in the next few months. Contracts will be over, and folks will be looking for bigger and better - maybe MotoX or SG4. there may not be a lot of support for this phone. I look at other Droid forums and realized that life is short lived with these phones.
So, having said all of athis, i may be sticking to stock or just run with a plain tried and true RC5 build on CM10.1
Good luck with your issue. happy mine was solved, the hard (but really easy way).