This may happen due to the storage being full in your web browser. If you are using Google Chrome as your web browser you will need to clear your storage by following these steps:
  • On your computer, open Chrome.

  • At the top right, click More .

  • Click More tools  Clear browsing data.

  • Choose a time range, like Last hour or All time.

  • Select the types of information you want to remove.

  • Click Clear data