This can be linked to your browser. We suggest you to try another browser like Chrome or Firefox.
If the different browsers don’t work, it could be related to a problem with your browser’s “cache”.
Here is the procedure to clear your browser cache:
Pour Chrome : https://support.google.com/accounts/answer/32050?co=GENIE.Platform%3DDesktop&hl=en
Pour Firefox : https://support.mozilla.org/en-US/kb/how-clear-firefox-cache
Does the problem persist? Take a screenshot of the malfunction and contact email@example.com or +32 (0) 2 505 08 80.