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Here are some common situations which can help when programming and collaborating in the ARENA.

Why can’t I hear you?

  • Don’t forget to make sure your computer speakers are not Muted or have your Volume set too low.

Can you hear/see me?

  • Audio/video setups vary a lot between web browsers so this can be common.
  • For Chrome, test your permissions and try different cameras/microphones: chrome://settings/content/camera and chrome://settings/content/microphone.
  • For Edge, in Windows Start > Settings > Privacy > Camera, and toggle the switch. Try the Microphone setting here as well.
  • For Firefox, test your permissions about:preferences#privacy, scroll down to Permissions, then Camera/Microphone and try different cameras/microphones:
  • For Safari, navigate your menus to Menu > Safari > Preferences… > Websites > Camera/Microphones and try different cameras/microphones.
  • Since we use WebRTC, try your browser at a third-party WebRTC test site

Where is my Object?

  • Is the object’s position below the ground? The y position will be negative below the default visible floor.
  • Is the object’s scale too big/small? Models especially have wild differences in scale, try increasing/decreasing the order of magnitude of the scale. Try a scale of 10, 1, 0.1, or 0.01.
  • Does the scene name in the URL match the scene name/topic where the object was created? e.g. URL is[your username]/example and MQTT topic published to is realm/s/[your username]/example/some_object_1.
  • Does the object appear in the left column of the A-Frame Scene Inspector?

Python Library arena-py Errors

While using the ARENA Python library, You may encounter an error condition due to your network configuration. Some of these are detailed below with some troubleshooting steps.

Python: MQTT connect error to, port=8883

If your internet connection uses a VPN or other firewall that may block port 8883, then the secure, encrypted TLS connection for ARENA MQTT will be prevented. To resolve:

  • Switch to another VPN, WiFi access point, or network connection that allows port 8883.
  • Use a SSH terminal connection to another server you operate that allows port 8883.

Python: Unable to get local issuer certificate

It seems some distributions of Python may not have any certificate roots installed for SSL. To resolve, some useful troubleshooting can be found online:

Web Browser Scene Errors

While visiting an ARENA scene in a web browser, you may encounter an error condition due to limited hardware, memory, or network capacity. Some of these are detailed below with some troubleshooting steps.

Error: Network speed is too slow

Some elements of the scene may not have loaded if at all. You may see this error if the network speed of your current connection is too slow for the ARENA to operate. Most fixes involve switching to another network connection which may have improved bandwidth or latency. Steps to try:

  • Switch to a different Wifi access point.
  • Switch from wireless network connection to wired (or vice versa).
  • Switch to another VPN or disable your VPN connection.

Error: Conference stream failed

You may see other users moving in 3d, but unable to see/hear their video or audio. You may encounter this error if some ports are blocked by a VPN, firewall, or other network filter. ARENA’s video conferencing system is backed by Jitsi, and requires the opening of additional ports to function. Our conferencing system requires the following ports to be open: 80, 443, 3478, 5349, 10000. Steps to try:

  • Switch to a different Wifi access point.
  • Switch to an alternate VPN channel or provider if possible.
  • Disable your VPN if one is in use.

Error: Conference server connection failed

Other users may have stopped moving completely. You may see this error if the network connection to the conferencing server has been lost. Steps to try:

  • Move your wireless computer/device closer to your access point.
  • Switch from wireless network connection to wired (or vice versa).
  • Switch to a different Wifi access point.

Warning: Events Publish Behavior is too high

You may see this warning when using AR Builder (ARB) or other editor tools to edit the scene in 3d. It is a reminder that the scene’s scene-options object is set to publish mouse events for every client and object in the scene, instead of only those chosen per object. This can lead to unnecessarily high MQTT events publish rates for complex scenes with many users.

  • Scene owners, remember to restore scene options to {"scene-options": { "clickableOnlyEvents": true }}.
  • In ARB this can be done by toggling the edit button off.

I have a different problem, where can I get help?

We have a place for submitting issues and asking questions in most of our code repositories: