.NET 4.0 and MMC snap-ins

[Michael Wojcik]

We have a large, complex project we just updated to use VS2010 and the
4.0 Framework.

Part of the project is an MMC snap-in for administration.

After the upgrade, I can no longer load the snap-in. I get this error
message from MMC:

-----
Could not load file or assembly 'MicroFocus.SEE.UI.SnapIn,
Version=4.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its
dependencies. This assembly is built by a runtime newer than the
currently loaded runtime and cannot be loaded.
-----

That *seems* fairly clear, and indeed there are various comments
floating around the Internet suggesting that you cannot load an MMC
snap-in built with the 4.0 Framework, because the MMC host doesn't
support it yet.

Except: everyone else on the team seems to be able to load the snap-in
just fine. Only my MMC complains.

I've uninstalled and reinstalled it manually using installutil, and
verified that it's using the correct installutil (the 4.0 one - any
other and it fails, as it should).

I'm on Vista Ultimate x64. Other team members are using Vista Ultimate
x64 or Windows 7 x64 - I don't know if anyone's tried it on Server
2008 yet.

Any suggestions, particularly for figuring out what's different on my
machine? If no one could load the snap-in, I wouldn't be at all
surprised. It's the inconsistency that I haven't been able to track down.

 

[PaulMead]

According to Microsoft it won't work. See https://connect.microsoft.com/Visua...4039/can-not-use-net-4-0-to-create-mmc-snapin Feel free to bump the "This is important" count at the top of the page.

 

[Michael Wojcik]

We have a large, complex project we just updated to use VS2010 and the
4.0 Framework.

Part of the project is an MMC snap-in for administration.

After the upgrade, I can no longer load the snap-in. I get this error
message from MMC:

-----
Could not load file or assembly 'MicroFocus.SEE.UI.SnapIn,
Version=4.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its
dependencies. This assembly is built by a runtime newer than the
currently loaded runtime and cannot be loaded.
-----

Resolution: tell MMC to use the v4 Framework. You can either set the
COMPLUS_Version environment variable appropriately (in my case, that's
to "v4.0.30319"), or set the Framework version in
%windir%\system32\mmc.exe.config.

The latter is left as an exercise for the reader, as I'm too lazy to
look up the details and test it.