For some reason my virtualmin disappeared this morning, we got a mail this morning that the disk quota was below 5GB of storage so i started looking through the machine to see if i could spot any unusual files. After a bit of searching we found that Bandwith monitoring was creating two 25GB log files (Should have read the description), because always better safe then sorry we decided the download the log file first before removing it. After a few minutes the webmin theme broke and others couldn't get to the the dashboard anymore. i changed the theme in the config file and when i restarted webmin Authentic theme did work but most of the dashboard wasn't displaying anymore, same with Virtualmin.
We managed to fix it by restoring a backup of the server in the end but if there is anyone who knows that might have caused this