VMware NSX
VMware NSX-T Data Center
To work around this issue, reboot the impacted ESXi host to:
Restore SSH responsiveness
Clear disk space constraints (if any) hampering the NSX upgrade
If the workaround outlined above does not resolve the issue, kindly collect the NSX support bundle and open a case with Broadcom Technical Support.
Collecting NSX Support Bundles
Following kb articles can be referred if reboot does not resolve your issue:
NSX upgrade failed with a ‘VI SDK invoke exception:org.dom4j.DocumentException’ error