Cannot load into Main Scene Under 2021.3.3f1

[hankashin]

forever loading

[AndreFoxVR]

I also cannot make it work (2021.2.0f1):

C:\Program Files\Unity\Hub\Editor\2021.2.0f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Preprocess.js:67
throw "Preprocessor error "" + e + "" occured in file "" + locals.inputPath + "" when evaluating expression "" + expression + """;
^
Preprocessor error "ReferenceError: HIDE_FULL_SCREEN_BUTTON is not defined" occured in file "C:/Users/Fox/Unity/Expo_Enap_R6/Assets/WebGLTemplates/Better2020/index.html" when evaluating expression " HIDE_FULL_SCREEN_BUTTON "
(Use node --trace-uncaught ... to show where the exception was thrown)
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)