When upgrading to a new YetaWF version which may include new or upgraded Visual Studio templates, it may occur that they do not work correctly, as the old version of the VS templates is still used. Apparently VS does a really good job of caching VS templates. So much so that new VS templates are totally ignored. Fortunately, there is a pretty simply workaround for this.
Open a Visual Studio Command Prompt and enter the following (may need to be done for every VS version you are using, with the matching VS Command Prompt):