You probably have checked these out already but I will throw them out there anyways .
In your MW2 main folder where reshade-shaders folder is is there a Reshade.fxh FX file ? I didn't have that for some reason once and it would not load the effects into the in game reshade menu.
Whats the effects path reshade is looking for the effects in ? When you open the menu under settings there should be a line showing where reshade looks for the effects I believe
Is the install asking you if you want to down load effects for reshade ? and they are checked i presume.
like i say i am figuring you have done these but just in case . as for the error that's for more seasoned guys to answer