Troubelshooting and recommendations
for video conferences

Technical Requirements

The University of Vienna’s e-learning video conferencing systems require either:

Please use the most recent version of either browser, if you can.

Other browsers may work not work well or at all and may even reduce call quality for all participants. This includes Apple Safari, Microsoft Internet Explorer, Microsoft Edge, Mozilla Firefox prior to version 78, and Opera.

Recommendations

  • Log on 5–10 ahead of time, so that you can address technical difficulties before the session starts.
  • Mute the microphone while you are not talking.
  • Use a head-set if possible.
  • Use a wired internet connection, rather than Wi-fi.

Common problems

Before trying the steps below, make sure that meet the technical requirements and follow the recommendations listed above!

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  • I can’t hear anybody!
    1. Make sure that haven’t muted your computer and try turning up your volume.
    2. Try unplugging and re-connecting your speakers. If your speakers use a phone connector, rather than USB, make sure that you have attached them the to speaker port, rather than the microphone one.
    3. Make sure your computer is using your speakers. You can check which device your computer is using to output audio by clicking on the speaker symbol in the lower right (Windows) or upper right (macOS) corner of your screen.
    4. Make sure that BigBlueButton, Collaborate, or whatever video conferencing system you are using, uses the correct output channel.
    5. Make sure your firewall and your browser allow WebRTC connections.

    If none of the above works, restart your computer. You may also want to try a different computer and/or a different internet connection.

  • Nobody can hear me!
    1. Did you mute your microphone?
    2. Try unplugging and re-connecting your microphone. If your microsphone uses a phone connector, rather than USB, make sure that you use the microphone port, rather than the speaker one.
    3. Make sure that BigBlueButton, Collaborate, or whatever video conferencing system you are using, uses the correct input channel.
    4. Make sure your firewall and your browser allow WebRTC connections.

    If none of the above works, restart your computer. You may also want to try a different computer and/or a different internet connection.

  • I get the error message “NotReadableError: Failed to allocate videosource”!

    Restart your computer and try again. If the problem persists, contact your vendor.

  • My camera doesn’t work!
    1. If you are using an external camera, make sure it’s connectecd to your computer.
    2. If you have a shutter for your camera, make sure it’s open.
    3. Make sure your firewall and your browser allow WebRTC connections.

    If none of the above works, restart your computer. You may also want to try a different computer and/or a different internet connection.

  • Ich hear an echo/a pulsing high-pitched noise!

    What you are hearing is a feedback loop. These may occur even when using a head-set. Reduce the volume of your speakers and then briefly mute your microphone as well as your speakers to stop the feedback loop. A small reduction of the volume typically suffices.

  • I occasionally hear a non-pulsating and quiet high-pitched noise!

    If you are participating in a hybrid lecture that takes place in of the Department of Philosophy's lecture rooms, then this is likely due to a technical issue with our equipment that we are at present unable to remedy. You may want to try to turn down the treble of your computer.

  • I can’t log on to Moodle!

    Get in touch with the instructor of your course immediately and then contact the Helpdesk of the Computer Centre (see below).