Apparently there are a lot of templates missing in themes for 2020.1 because themes are older than the current SCA version. This is apparently a known issue when running gulp extension:local

1. On theme-devtools directory go to the file gulp/extension-mechanism/client-script/LoadTemplateSafe.js and edit the function wrapDefine(func) adding two calls to the method insertPlugin(deps). (See the attached file patch.png) 2. Remove the file LocalDistribution/javascript-libs.js 3. run gulp theme:local