Microsoft Sync Framework Unhandled Exception “Retrieving the COM class factory for component with CLSID…”

From the Microsoft Sync Framework 2.1 SDK download page

in the last part where it says instructions:

It is not possible have full 32-bit Sync Framework 2.1 SDK installed side-by-side with the 64-bit SDK; therefore you will have to install one version of SDK (64-bit) completely and only selected components of other version (32-bit) of SDK. See Sync Framework Tips and Troubleshooting topic for details.

But that statement isn’t totally clear: The way to install for 64bit development machine is to download the x64 for the SDK and the fill the x86 parts with the redistributables from

It works for me at least. Hope it helps.

Unrelated tidbit: I broke the Microsoft Forums layout when I posted this as a reply to

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