Minimum Free Disk Space Reached

I've Just set-up a new Single Instance Splunk Server (Version 7.3.2) on a VM with 200GB of space. I've not set up any indexes/searches/apps etc I've literally only run the installer and logged in to the web page. Why am I getting the following error when I have so much free space on the VM? "The minimum free disk space (5000MB) reached for /opt/splunk/var/run/splunk/dispatch"