Generally, the MissingKey/Cookie error you are facing is caused by your web browser blocking third-party cookies. Each browser acts differently, but below are instructions on how to allow those cookies in Chrome, Safari, and Firefox:


Chrome:

  1. Open Chrome preferences click on Settings, then Show Advanced Settings.
  2. Under Privacy, click on Content Settings.
  3. Make sure "Block third-party cookies and site data" is not checked
  4. Refresh your page (if a normal refresh doesn't work, try clearing cache* and refreshing).


Safari:

  1. Go to the Safari drop-down menu (top left, beside the apple icon).
  2. Select Preferences.
  3. Click Privacy in the top panel.
  4. Uncheck Prevent Cross-site Tracking. (Note: Safari has an interesting glitch. If this is already unchecked, try checking it, then unchecking again).
  5. Refresh your page (if a normal refresh doesn't work, try clearing cache* and refreshing).
  6. If the issue continues after refresh, try going back to the Privacy tab and unchecking Block all Cookies.


Firefox:

  1. Go to the Firefox drop-down menu.
  2. Select Preferences.
  3. Click Privacy.
  4. Under Cookies, select the option 'Accept cookies from sites.'
  5. Refresh your page (if a normal refresh doesn't work, try clearing cache* and refreshing).


* For instructions on clearing your cache, see this document: How to Clear Your Browser Cache