Please keep in mind that Vizible does not officially support Windows Mixed Reality yet, however we've seen success with users if they follow the below steps.
Go here to download and run the Vizible installer. Just accept all default options for the install.
With Steam VR installed, Search in Steam for Windows Mixed Reality and install.
Launch WinMR by clicking the desktop icon shown below, then launch SteamVR:
Only once Steam VR is running, turn on the right hand controller first and then turn on the left hand controller. Only this will ensure you have the correct visual hands showing up in Vizible. If you don't do this, the app will still work, the hand controllers just might be mixed up.
At the launcher window, use the “Download Assets” option to download the meeting assets first. Then you’ll be able to very quickly sign into the meeting at the scheduled time.