If you usually play on FB:

Update or re-install flash
Clear your browser cookies/cache
Try a different browser or PC
Try accessing it on your mobile phone (if you can)
Try accessing it through: Play Now - Top Eleven be a Football Manager rather than on Facebook (just use your FB login details)

If you are playing on a Mobile device:


Try uninstalling and reinstalling the App
Try accessing it through a browser on your device
Check that flash id up to date and that you have enough free memory to run the game

If that fails contact Nordeus Support : Nordeus Support