This can of course be due to an inconsistent internet connection, but this message can often appear for players using Internet Explorer 8. This version of IE is no longer compatible with Facebook, and can cause issues on Facebook and in other games too.
If you are using Windows XP, you will not be able to update your browser past IE 8. In this case, we recommend using a different browser, such as Chrome, which you can download for free by clicking here.
If you are not sure what browser or version of Windows you are using, click here to view your support details.