Dude need help also. i have Lenovo A328, when i edited my build.prop i forgot to change the permisssions and then i rebooted it. unfortunately it ends up in black screen. and i cant seem to fix the problem using update.zip. it always says INSTALLATION ABORTED.
if you want i can send the update.zip.
Which ROM do you use? If you have a tweak.prop file located on your phone, you should be fine reflashing my zip, otherwise your (hopefully custom) ROM can be flashed over to fix it, too.