[Nick Sandulli]

Hi everyone!

I was hoping for some help! I bought my phone off swappa and it was rooted when I received it. It never caused me any troubles until now when I tried to update to lollipop and I got this message:

"The operating system on your device has been modified in an unauthorized way. Try downloading software updates using Samsung Kies on your PC, or visit a customer service center."

I unrooted it using the SuperUser method and I still have not been able to update. Is there anyway to do this without performing a factory reset? I really do not want to spend the time reinstalling everything. Thanks!

[Rukbat]

1) [GUIDE] Backing up an Android Phone. It's not that difficult to back up the phone.

2) The root process is supposed to"fail" if there are any signs that the phone has ever been rooted. There are things you can do while rooted, that remain after you unroot, that could cause an update to brick the phone.

Back it up, flash the stock ROM and let it update.