“Cannot run upgrade script on host” during upgrade from ESXi 5.1 to ESXi 5.5

The host upgrade from ESXi 5.1 to ESXi 5.5 failed at 93 percent with the following error: „Cannot execute upgrade script on host“.

I found two possible issues – the second one worked for me:

Issue 1: /bootbank/state.xxxxxxxx directory not empty

Take a look at KB 2007163 „Upgrading a VMware ESXi host fails with the error: Cannot run upgrade script on host“

Issue 2: troubles with the FDM agent (former HA agent) from the host

In my case issue 2 was the problem – performing the steps descriped below did the trick for me.

I found the following message in the /var/log/vua.log:

[FFD0D8C0 error ‘Default’] Alert:WARNING: This application is not using QuickExit().

The exit code will be set to 0.@ bora/vim/lib/vmacore/main/service.cpp:147

–> Backtrace:

–> backtrace[00] rip 1bc228c3 Vmacore::System::Stacktrace::CaptureFullWork(unsigned int)

Resolution:

• disable HA for the cluster
• remove the ESXi host from the cluster
• connect  via SSH to the ESXi host and run the following commands to uninstall the FDM agent:

(as also descriped in KB 1003714 „Verifying and reinstalling the correct version of the VMware vCenter Server agents”)

cp /opt/vmware/uninstallers/VMware-fdm-uninstall.sh /tmp
chmod +x /tmp/VMware-fdm-uninstall.sh
/tmp/VMware-fdm-uninstall.sh

• reboot the host

Now you can re-add the host to the cluster and perform the upgrade to ESXi 5.5. Do not forget to enable HA again…