You can access vRealize Operations for Horizon broker and desktop agent log files for troubleshooting.
Broker agent log files are located in C:\ProgramData\VMware\vRealize Operations for Horizon\Broker Agent\logs on the Horizon Connection Server host where the agent is installed.
Desktop agent log files are located in C:\ProgramData\VMware\vRealize Operations for Horizon\Desktop Agent\logs on the remote desktop being used.
You can also use the vdmadmin command to create a Data Collection Tool (DCT) bundle that contains log files from one or more remote desktops. For more information, see the Horizon Administration document for your version.