I want to define an external driver model. I have generated the drivermodel.dll but am getting the error 'Loading DriverModel dll 'C:\...\DriverModel.dll' failed. Windows error message: %1 is not a valid Win32 application.' What is the problem?

There is likely a 32/64-bit mismatch. After compiling the DLL in the bit-version matching that of PTV Vissim, you should no longer receive this error.