If you ever tried to build some custom activities in TFS 2010 Build you’ve probably run into the following error message:
TF215097: An error occurred while initializing a build for build definition \TeamProject\MyBuildDefinition: Cannot create unknown type '{clr-namespace:[namespace];assembly=[assembly]}Activity
This means that the TFS build service couldn’t create an instance of the customer workflow activity that is referenced inside your build process template.
So here is a short checklist with some possible reasons:
- You have checked in the modified version of the XAML workflow.
- Your custom activity has the the BuildActivityAttribute.
- Your custom activity is public.
- You have configured your build controller with the path in source control where the custom activities are located .
- Verify that all dependencies for the custom activity assembly/assemblies have been checked into the same location as the assembly.
- The reference to the custom activity assembly in the XAML workflow is correct.