Home/ Questions/Q 9214503
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-18T01:59:07+00:00

Not sure if anyone else is having this issue. I am attempting to create

  • 0

Not sure if anyone else is having this issue.

I am attempting to create a windows forms library control. I need the control to run in an x86 environment. So, the first thing I do is go into the properties of the project and switch the platform target to x86.

I try running the application and I get the lovely error message referencing the assembly I am trying to create and stating: An attempt was made to load a program with an incorrect format.

I have not added any references nor any code, just trying to create a control in x86.

I am using a windows 7 64bit machine with VS2012 trying to write the app in .NET 4.5. I have to do the project in x86 because I am using some OCX that are x86 only.

Has anyone run into this?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    go into the properties of the project and switch the platform target to x86

    Well, that worked. Instead of a confusing COM exception (typically “Class not registered” which has several possible reasons) you get an early .NET exception that tells you that you are using the library wrong.

    To test your library project, you needed to create an EXE project that had a reference to the library project. What you forgot to do is change the Platform target setting on that EXE project. Which matters because only the EXE project can determine what the bitness for the process will be. It is the one that loads first, a library project has no say. It can only veto the choice, the BadImageFormatException is that veto.

    So you have to change the Platform target setting for the EXE project to x86 as well.

    • 0