I suspect that will need to be updated to work with 4.3. Try the hotspot mod instead: [MOD][Deodex][Odex][MB1][MC3][MD4][MK3]Hotspot Mod - Working 4G - xda-developers
I updated my s3 two days ago to 4.3, after i had updated i realised that i had lost my root and could no longer tether. I re-rooted but i still can't wifi tether to work (it starts with errors), I uninstalled 3.2 and then installed 3.3 with hopes this would fix whatever the problem was but still got the same message, in addition to that i could no longer view the show log (says file does not exist). so re-installed 3.2 but i still cant access the show log. Any help would be greatly appreciated!