QB Issue Resolution:

To clear history and cache in Firefox

  1. Click the menu icon (looks like three lines) in the upper-right corner and select History.
  2. Click Clear Recent History.
  3. A pop up window will open; if a Time range to clear option is present, set it to Everything.
  4. If a list of check boxes is not visible, click the down-arrow button next to Details to reveal them.
  5. Make sure there are check marks next to Cache.
  6. Click Clear Now.
  7. Close all open Firefox windows, restart the browser, go to the sign-in page for QuickBooks Online and try again.