(CLR Action): Could not interpret instance of ... in managed code custom action

Hello,

I'm trying to create a new managed code action in Suite (IS 2014), following step-by-step example from Help (Working with a Managed-Code Action in a Suite/Advanced UI Installation). But looks like installer hits a problem loading this managed module at run time. In the debug log I see:

7-31-2014[06:43:25 PM]: Running event 'NewAction'
7-31-2014[06:43:25 PM]: Engine: request for proxy handler, 0, 0
7-31-2014[06:43:27 PM]: (CLR Action): Attempting to load through CLR 4 APIs...
7-31-2014[06:43:27 PM]: (CLR Action): Getting meta host...
7-31-2014[06:43:27 PM]: (CLR Action): Enumerating available runtimes...
7-31-2014[06:43:27 PM]: (CLR Action): Highest available runtime: v4.0.30319
7-31-2014[06:43:27 PM]: (CLR Action): Trying to use highest runtime...
7-31-2014[06:43:27 PM]: (CLR Action): Using highest version runtime...
7-31-2014[06:43:27 PM]: (CLR Action): Could not interpret instance of TestCLRClass
7-31-2014[06:43:27 PM]: Action 'NewAction' returned status 0x00000643

Should I use some non-default settings in Visual Studio to build this managed module? Or any other "gotcha" for using managed code in Suite? I'm looking for any help, I have no idea how I can debug this problem. If you have any references to some examples or test projects please share them with me.

Thank you,
Tiller.