If you receive this error please logout, close your browser, reopen it and trying logging in again. You should now be able to login and should not receive this error again in future.
If the error still persists please clear your cached images and files in your browser. If you are using Chrome you can perform this by selecting 'Clear browsing data...' as per the image below:
If you still receive the error message please contact disciplinary@thefa.com who will check that the correct permissions are assigned to your account for access.