Same issue here. It started when I added some fields to the on-screen template. Even after removing those fields, the white space stays. It didn't affect just me, all of our users are experiencing the same issue, even those that have never selected the template I made changes on. Uninstall/Reinstall may sound great, but we are on a remote server with 30 users, so it takes quite a coordinated effort to perform any changes/updates to QBE.