Managed Custom Action (Wix) Error

I had to write a few custom actions for a wix installer. I didn’t have any experience with using managed custom actions in wix so I started with a good article about this.

I implemented all the steps described in the article and ensured that everything is ok but I was still getting the error: “InstallUtilLib.dll: Unknown error.”

After some investigation (tests and internet search) I understood that you have to specify the supported .net framework in the configuration file in case you have installed more than one framework:

<?xml version=”1.0″ encoding=”utf-8″ ?>
<configuration>
 <startup>
  <supportedRuntime version=”v2.0.50727″/>
 </startup>
</configuration>