Is there a way to uninstall the latest update on the ZTE blade zmax phone? Ever since I installed the latest update on the ZTE blade zmax phone I can't hear incoming calls and some outgoing calls.
If it can be done at all, it cannot be done easily. Try first a Cache Partition wipe. If no go, consider a full Backup and Factory Reset. You would have to do that anyway if trying to revert to an earlier version of the OS, and Factory Reset is much easier.
Tell us if you need advice about backing up as much as possible of your personal data.