A completely blank page on the Dashboard may be due to different causes, but if no information is showing, you should be able to see the Dashboard once again simply by refreshing (reloading) the page.
If you got the blank page after clicking on a link to a student's OLA, please try logging in to the Erasmus Dashboard first, and then try opening the link once again.
If this does not work and you keep seeing only an empty page, please use the bug report page or the "Found a problem?" button on the Dashboard page, if you can see it.
When reporting the bug, please specify that you have already tried what suggested here and attach a screenshot.