Can I get any tips on this purple screen. It appeared last night and the server recovered after a reboot.
As I can see your esxi build version is very old . try to update latest one .
https://kb.vmware.com/s/article/2143832
ESXi 5.5 Update 1 2014-03-11 1623387.
latest build version
ESXi 5.5 Update 3f 2017-09-14 6480324
Also check your hardware firmware version .
As I can see your esxi build version is very old . try to update latest one .
https://kb.vmware.com/s/article/2143832
ESXi 5.5 Update 1 2014-03-11 1623387.
latest build version
ESXi 5.5 Update 3f 2017-09-14 6480324
Also check your hardware firmware version .
The issue is likely the one covered in https://kb.vmware.com/s/article/2079094. If so you may consider to update/patch the host.
The current build number is 7618464 (Jan 22, 2018). Please make sure your host supports this version prior to run the update.
André