Originally Posted by JuggerMod
Eg. Say your trying to mod mw3 campain(example) and your using modio and have the .svg open in modio and then you want to open it up in horizon at the same time you will get that error messege so you would have to close modio to mod it on horizon.
Modio is just another example it can be any program.
I think it's because the device explorer isn't working right