clr.AddReferenceToFile() fails in IronPython 2.7

Can someone explain why this code:

im开发者_开发百科port sys
sys.path.append("C:\\WINDOWS\\system32")

import clr
clr.AddReferenceToFile("wiimotelib.dll")

works fine with IronPython 2.6, but fails in IronPython 2.7 alpha 1 with an IOException, and the message:

Could not add reference to assembly wiimotelib.dll

Is this new behaviour in 2.7, or is it an alpha release bug?

Could this be a .NET 2 vs .NET 4 problem? IronPython 2.7A1 is .NET 4.0 only. 2.6 had both .NET 2 and .NET 4 versions. If the assembly is a .NET 2 assembly it might not load on the .NET 4 CLR.

You have to recompile the WiimoteLib Assembly. I've had the same problem. After recompilation it was gone.

I think in IronPython 2.7 was removed the need for the "DLL" extension:

You could try: clr.AddReferenceToFile("wiimotelib");

Worked for me.