Observation
When clicking on the dialling button of the ProCall app for Microsoft Teams, the following message appears:
Example screenshot: Microsoft Windows system message - Sorry, the call could not be completed
However, incoming calls are signalled normally with a ProCall call window. Calls can also be triggered directly via ProCall.
Cause
From the ProCall app for Microsoft Teams, the call is initiated via a Tel-URI to which the ProCall client for Windows should respond on the system. The first time the call function was used, the user selected an incorrect application for this tel URI and saved it in the system.
Troubleshooting
This Tel-URI has been initialised by ProCall in the Windows registry (Computer\HKEY_CLASSES_ROOT\tel\shell\open\command) with the ProCall program path for many years, but can of course also be overwritten by other programs.
In current Windows environments, this entry no longer has priority. Microsoft Windows manages this under Settings → Apps → Standard Apps → Select default values by link type → TEL and ProCall must be selected here.
Example screenshot: Microsoft Windows Settings - Select default value by link type
Login to ProCall app for Microsoft Teams fails
ProCall app for Microsoft Teams is not displayed correctly
