You can put the VDI in maintenance mode from Horizon Admin Console and then try the below steps:
1. Uninstall Horizon Agent
2. Reboot the machine
3. Uninstall VMware Tools
Important: You can install the VMware Tools from mounting it directly from ESXi or you can download the VMware Tools installer from VMware Downloads and store it in the VDI machine itself. Also, if you have GPU card attached, remove them first as you will not have VM console access and you need it after removing VMware Tools.
5. Reboot the machine
6. Reinstall VMware Tools, Reboot
7. Reinstall Horizon Agent and reboot and check the status of the VDI in Admin console by taking it out of maintenance mode.
Note: If you have any other VMware components installed such as App Volumes Agent, UEM/DEM Agent or VROPS Agent, please follow the proper sequence to remove them before uninstalling Horizon Agent.
If the issue still persists, please try the token reset as per the VMware KB 2038679 as mentioned in the last reply by ARomeo.