Steps to reproduce:
After upgrading from zabbix 4.0 to 5.0.3 my vmware monitoring stopped working. My vmware version is 4.1.
On logs I found this response from vsphere SOAP response:
Then I looked for vmware docs and found this: https://vdc-download.vmware.com/vmwb-repository/dcr-public/da47f910-60ac-438b-8b9b-6122f4d14524/16b7274a-bf8b-4b4c-a05e-746f2aa93c8c/doc/vim.host.MountInfo.html
There it says that "mountInfo.mounted" is available since vSphere API 5.0.
Zabbix docs says: The minimum required VMware vCenter or vSphere version is 4.1. (https://www.zabbix.com/documentation/current/manual/vm_monitoring)
On my lab, removing only this property at the request made it work OK again.
See attached patch file...