An infinite loop is a loop that continues with no sign of stopping. It is usually an unintended side-effect of a bug in a computer program.
For example, when a web browser attempts to load a page it can sometimes get stuck in a continuous loop - while the browser indicates that it is still loading the page, the user doesn't see any significant change or any visible sign that components of the page are being loaded. If the browser was not manually stopped by the user, it would likely continue looping forever.
Quite often, people have said that they experience continuous (or infinite) loops while attempting to log in to a private Wikidot site. This problem is yet to be fixed as Wikidot has not yet determined the cause of the problem.
If you experience this issue yourself, please post a reply on the feedback website here with information about the Operating System and Web Browser settings that you are using.