take a backup and wipe dalvik/cache and system ... and install the zip again u clear dalvik and cache only ! reboot
else u need to do a fastboot flash using the stable images rom
goto twrp, clear dalvik, cache and system ( not data ) and then install this rom ... it shud work without u losing the data.
else u can adb sideload the zip rom but u have to clear dalvik,cache and system before u proceed !