Constant "Preparing Network" notification on TW ROM -- my fix
I finally got around to rooting and installing the updated, Knox-free TouchWiz MK5 ROM on my Galaxy S3 (Virgin Mobile), but I hit a problem that some others have seen, including on this post
and several others
where the phone will not connect to 3G nor 4G wireless and it has a constant "Preparing Network" notification on the taskbar. Trying to run the activation on the phone fails, and when I tried to manually update the PRL or Profile, it just says "Session already in progress, please try again later".
Since I'm fairly new to the board, I couldn't post a reply or question in the DEV threads, but hopefully the solution I had to take will be helpful to others.
I started from a Knox-free MD7 build on my S3 and just followed the root and then MK5 ROM update directions
... all of that went cleanly.
The fix was
to * Update the Modem to MK5
* as well!
After updating the modem software to match the ROM, a quick reboot later and the activation worked now and, after a couple of minutes (and maybe another reboot or two) it updated the PRL and Profile and both 3G and 4G LTE were working again!
Looking back now, though, I realize that I got carried away with playing with the new ROM after Step 7 of @jdsingle76
's directions and I failed to follow Step 8...