After I found HP’s version of 6.5 wasn’t stable yet : http://pariswells.com/blog/random/hp-vmware-6-5-psod 

We needed to roll back to v6 UP2

You can usually do this if you’ve done an upgrade by Pressing SHIFT and R on the Vmware load screen and roll back to the old version. For some reason the upgrade process had not set a restore point so we will have to do this manually.

I did try the below method of backing up and restore the config files , however this does not work between versions 🙁 

Source code

vicfg-cfgbackup.pl --server ESXi_host_IP_address -s backup.tgz
 
vicfg-cfgbackup.pl --server=ESXi_host_IP_address --username=root -l backup.tgz
 
vicfg-cfgbackup.pl --server=ESXi_host_IP_address --username=root -r

So we will have to do this manually

Settings to copy down before reinstall.

1. IP/Subnet/Gateway and DNS of Server
2. All VSwitch Configurations ( Names , Vlan ID’s ) as well as VKernel IP’s
3. Make sure if your using NFS You get the paths for these , also check the VSwitch Active Active Settings ( E.g. IP Hash ) 
4. Scratch Disk Locations ( Click the Configuration tab, then click Advanced Settings under Software. Ensure that Syslog.global.logDir  )
5. NTP Settings

Reinstall server from scratch and reenter manually