RE: Quickbooks QBFC 80040154 "Co-Create error"?

Previously I had problems getting a desktop application to integrate with QuickBooks on a 64 bit Windows Server 2008 operating system running IIS 7.0.  Recently I've moved my development Website to the same 64 bit machine, and I was experience same problems with getting my .Net website to be able to use the QuickBooks QBFC8 Library.  Thanks to some experience from before I knew I should see if this was a problem going from 32 Bit to 64 Bit.  It was.  I had to "Enable 32-bit Applications" in the Advanced Settings on the Application Pool.

Quickbooks QBFC 80040154 "Co-Create error"?

Today I got "Retrieving the COM class factory for component with CLSID {EE7620FE-2EE1-4077-8A52-E485E85DD6B1} failed due to the following error: 80040154." Found out it was because I was including multiple instances (different versions) of the same class (QBFC4,6,8) so excluded the old dlls and everything worked.

QuickBooks SDK 8.0, QBFC8 and Windows Server 64 Bit

Was having problems with QB SDK 8.0 not working properly, discovered via intuit developer forum that I needed to force x86 compilation instead of "Any CPU".  Was getting an error similar to "Could not find the COM Class with CLSID *****-******....".  Switched the compilation method to x86 explicitly, and it started working.  Yay!