I had this wierd Error where I could not add a new Orchestration to my project.
I did not find the template for it when I clicked Add New Item.
Luckily I remembered I had installed a hotfix a day before and that could have messd the Template bindings.
So I knew I had to install only the templates again.
I did it by running the following command as mentioned in the link below and it helped.
I restarted Visual Studio and my templates were back again.