.net interface to COM server fails with 0x80080005

cominteropnet

I have a native c++ COM server that exposes COM interfaces. I can successfully use a native c++ client application to get and use the exposed interfaces from the server.

When I use a .net client with a reference to the server, I get the error:

Retrieving the COM class factory for component with CLSID {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} failed due to the following error: 80080005 Server execution failed (Exception from HRESULT: 0x80080005 (CO_E_SERVER_EXEC_FAILURE)).

…even though the COM server starts and runs successfully (and only takes about 1 or 2 seconds to startup).

BUT I get the above error only when the server is registered as a local server. If I register the server as a windows service, the .net client can successfully get and use the interfaces just fine.

I'm doing all this as an admin on Windows 7 64-bit. The COM server is on the local machine.

I checked the thread below, but no answers were offered:
Retrieving the COM class factory for component with CLSID {XXXX} failed due to the following error: 80080005

Spent a day and a half on this one so far…what could be the problem?

More information:
I've had this working with vs2005. I recently updated to vs2010 and am now running into this issue. I've tried building the .net client targeting frameworks 2.0, 3.5, and 4.0 with the same results.

Thanks

Best Answer

I was seeing this error when using a .net app running on x64 to try to connect to a 32 bit COM app. I was able to fix it easily by switching my .net app to x86 (32 bit).

Related Solutions

Retrieving the COM class factory for component with CLSID {XXXX} failed due to the following error: 80080005

Seems to be a rather generic error relating to starting up the COM server. Possible issues include timeouts, logon failures (check the Q about CO_E_SERVER_EXEC_FAILURE), or security permissions, or (evidently) a VS2008 ATL bug. Hitting an error in CreateInstance would do the trick as well, I think.

I'd start by checking Event Log for anything interesting.

.net – Difference between decimal, float and double in .NET

float and double are floating binary point types. In other words, they represent a number like this:

10001.10010110011

The binary number and the location of the binary point are both encoded within the value.

decimal is a floating decimal point type. In other words, they represent a number like this:

12345.65789

Again, the number and the location of the decimal point are both encoded within the value – that's what makes decimal still a floating point type instead of a fixed point type.

The important thing to note is that humans are used to representing non-integers in a decimal form, and expect exact results in decimal representations; not all decimal numbers are exactly representable in binary floating point – 0.1, for example – so if you use a binary floating point value you'll actually get an approximation to 0.1. You'll still get approximations when using a floating decimal point as well – the result of dividing 1 by 3 can't be exactly represented, for example.

As for what to use when:

For values which are "naturally exact decimals" it's good to use decimal. This is usually suitable for any concepts invented by humans: financial values are the most obvious example, but there are others too. Consider the score given to divers or ice skaters, for example.
For values which are more artefacts of nature which can't really be measured exactly anyway, float/double are more appropriate. For example, scientific data would usually be represented in this form. Here, the original values won't be "decimally accurate" to start with, so it's not important for the expected results to maintain the "decimal accuracy". Floating binary point types are much faster to work with than decimals.

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