dll - Class not registered Error

Question

Running an application from Visual Studio 2012 on 64-bit computers, displays the following error message:

Retrieving the COM class factory for component with CLSID {F2D4F4E5-EEA1-46FF-A83B-A270C92DAE4B} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))

I am using Inventor packandgo dll library in visualstudio.

Anyone know what is the error?

Answer 1

My problem and the solution

1. I have a 32 bit third party dll which I have installed in 2008 R2 machine which is 64 bit.

2. I have a wcf service created in .net 4.5 framework which calls the 32 bit third party dll for process. Now I have build property set to target 'any' cpu and deployed it to the 64 bit machine.

3. When Ii tried to invoke the wcf service got error "80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG"

4. Now Ii used ProcMon.exe to trace the com registry issue and identified that the process is looking for the registry entry at HKLMCLSID and HKCRCLSID where there is no entry.

5. Came to know that Microsoft will not register the 32 bit com components to the paths HKLMCLSID, HKCRCLSID in 64 bit machine rather it places the entry in HKLMWow6432NodeCLSID and HKCRWow6432NodeCLSID paths.

6. Now the conflict is 64 bit process trying to invoke 32 bit process in 64 bit machine which will look for the registry entry in HKLMCLSID, HKCRCLSID. The solution is we have to force the 64 bit process to look at the registry entry at HKLMWow6432NodeCLSID and HKCRWow6432NodeCLSID.

7. This can be achieved by configuring the wcf service project properties to target to 'X86' machine instead of 'Any'.

8. After deploying the 'X86' version to the 2008 R2 server got the issue "System.BadImageFormatException: Could not load file or assembly"

9. Solution to this badimageformatexception is setting the 'Enable32bitApplications' to 'True' in IIS Apppool properties for the right apppool.