A factory reset will not work in this case, the files that were modded are in the system/framework folder. A factory reset only resets the data partition. You have 2 choices at this point. Odin the MK2 tar file to return you phone to stock and then reroot your phone. Install a custom recovery and then flash the correct hotspot mod found below.
Or, if you have a custom recovery installed, you can try to flash the hotspot mod below to correct your errors. If you don't have a custom recovery installed then try to odin one to your phone and install the mod below.
If you tried to do a manual hotspot mod, you probably forgot to set the permissions after copying the files so you can try the fix permissions setting in a custom recovery also.
Phones & Tablets: Galaxy S4, Galaxy Note 8", Evo 4g LTE, Evo 3D, Acer Iconia A500, Samsung Galaxy Tab 2 10.1, Ipad 2, Nabi 2,
Rom: Rooted Stock Odexed, Hotspot Mod, Xposed, Wanum, several other xposed tweaks