FlexiTime runs in the your browser's Flash player plug-in. That's how we deliver such a rich user experience.
Generally on Microsoft operating systems or when using Chrome, Flash is kept up to date and you will never have any problems running FlexiTime.
Recently Apple released a patch that disabled older versions of Flash in Safari and Firefox. Some of our users have found they get a blank screen or are prompted to update Flash when they try to use FlexiTime or any other website with Flash content.
The place to get a Flash update is here:
If you see an image of a bouncing cube when you go here, then Flash is up to date and working. If not, it is reasonably simple to download the latest version from this website.