Since I don't know what the error means, I can only guess what could cause issues...
I think your Geforce Experience version is outdated, the latest version should run fine with sweetfx and enbseries so update that one.
Your DirectX version might be outdated, the latest should be found here http://www.microsoft.com/en-us/download ... aspx?id=35
A quote from the Enbseries site if you have trouble with using it:
Other then that I don't know why it should crash, maybe a missing MS Visual C++ Redistributable version.d3dx9_26.dll, d3dx9_40.dll, d3dx9_43.dll - required to run ENBSeries, if game won't start with modification and display error message, download DirectX Runtime from microsoft.com web site, they are not exist in system only for those users, who did not update DirectX several years or did clear installation of OS recently. If you need them, unpack to same folder, where ENBSeries is. Also you can put these files in to system folder of your windows installation.