Thanks guys for the replies!
The thing is, I haven't touched the code in a few months I guess.
When I try to access the admin site in the browser, it gives me a blank site as well. I can login, but it then refers to a blank side.
I uploaded a fresh download to a new folder on my server. The check function works and shows all documents are fine, however the install.php also gives me a blank page. I believe it has to do with my server then?
Thanks and cheers,
Pierre