State of knowledge

October 2021

Possible reasons


Version current or update required?

The first thing you should investigate is whether you are using the latest version of your browser (be sure to check the  System requirements as well):

Check permissions

When you join a meeting, a permission request is made via the browser for access to the camera and microphone. If you have accidentally clicked Block here, you can grant access again by clicking the corresponding icon in the address bar. Note that this works differently depending on the browser.

See the documentation for further instructions.


In the browser settings you can manage the microphone and camera:

Clear browser cache and cookies

It may be necessary to delete the browser cache and cookies for First, check if access to the camera and microphone works in an incognito/private browser window. If so, clearing the cache and cookies of the web application may help:

Camera is blocked by another application

The browser will not allow access to the camera if another application or even another browser window already has access to the camera. Stop access because of this and try again in ProCall Meetings.

System settings

Microsoft Windows 10/Windows 11

Check in Windows Settings → Sound the corresponding input device (microphone)

For the camera, check under Windows Settings → Privacy settings for the camera and microphone whether access to the camera and microphone in general is given and also in particular if the browser is allowed.

Apple macOS

Starting with macOS Mojave, there are some system-wide privacy options that can block access to the microphone or camera.

Check the operating system documentation for the appropriate settings:

Checking the environment with the WebRTC troubleshooter

With WebRTC Troubleshooter you can check camera and microphone for functionality:

If errors are displayed here in connection with the devices, this indicates that the devices used do not work in connection with the browser and WebRTC.


Strict firewall rules may prevent the camera and microphone from working. Therefore, please note the system requirements.

Further procedure