Samsung uses a pretty clever method to find out if a user has flashed a custom ROM or kernel or in any way tampered with the official software i.e the flash counter on their Galaxy line of devices, which gets incremented whenever a custom kernel or boot file is flashed on the device.
If you’ve somehow managed to trip the flash counter on your Verizon Galaxy S3 and would like to reset it, XDA Forum Member enderblue has posted a detailed guide on how the flash counter can be reset. The procedure needs root access to work and involves a few commands that need to be entered from a terminal or through ADB on the computer. enderblue believes the procedure might also work on the Sprint, T-Mobile and AT&T variants, though those are all untested.
It is to be noted that it can be dangerous to try the flash counter reset procedure and must be tried at the user’s own risk, though it mostly should work without problems. Head to the official page on XDA where you can get the instructions on how to reset the flash counter on your Verizon Galaxy S3. Do let us know how it works!