Could not load file or assembly 'PDFLibNet' or one of its dependencies

I'm running into an issue that it says pdf lib doesn't match the .netversion I'm using.

The problem is I'm using the same version on both

Microsoft .NET Framework Version:2.0.50727.9031; 
ASP.NET Version:2.0.50727.9031;
PDF Lib: v2.0.50727;

LOG: Attempting download of new URL file:///C:/Projects/bin/PDFLibNet.DLL.
ERR: Failed to complete setup of assembly (hr = 0x8013101b). Probing terminated.
[BadImageFormatException: Could not load file or assembly 'PDFLibNet' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded.]

Figured it out for some reason it was referencing the wrong one in my webservice/BIN folder after I removed the .dll file it pulled the new one and that fixed it!