Solution:

Follow the steps below to clear cache and cookies from Mozilla Firefox:

Mozilla Firefox 67 and higher

1. Click the Menu icon in the upper-right:
   
   
2. Click on Library.
3. Click on History.
4. Click on Clear Recent History....
5. In the Time range to clear: drop-down menu, select Everything.
6. Check the applicable boxes for Cookies and Cache.
7. Click the Clear Now button.
8. Close all Mozilla Firefox browser windows.