M-files Desktop Client - button to toggle between old and new versions is missing.

Your administrator may have hidden the toggle. Technical details in section 3 of Quick Guide - New User Experience for M-Files Desktop.

Another possible reason is a change in your desktop client’s connection protocol. The new M-Files Desktop requires a gRPC connection to the server. This setting normally doesn’t change on its own, but administrators may sometimes update vault connection configurations.

Your administrator may have hidden the toggle. Technical details in section 3 of Quick Guide - New User Experience for M-Files Desktop.

Another possible reason is a change in your desktop client’s connection protocol. The new M-Files Desktop requires a gRPC connection to the server. This setting normally doesn’t change on its own, but administrators may sometimes update vault connection configurations.

Thanks so much for your guidance Joonas.  You are a lifesaver.  I had to go to Admin and go to Configurations \ Advanced Vault Settings \ Configuration \ Client \ Web and New Desktop \ M-Files Desktop Settings.  I appreciate your help!