The issue was possibly caused by workflow toolkit version between Inventor and AMEP, could you please check following below steps:
1. Close all software applications.
2. Navigate to your product installation folder; for example C:\Program Files\AutoCAD MEP 2010.
3. Select the file WorkflowBase-1_0-vc90-wt.dll, right-click go to the Details or Version tab check the File Version.
If the file version is not 188.8.131.52 or newer then you do need to install this hotfix.
you can get the hotfix at below location:
Please let me know if this does not work for you.
With the AutoCAD MEP Hotfix, it works now. I could import the adsk file into MEP.
I defined some connection point on my model into Inventor, and I can't find them after importing the model into MEP. Is it normal ?