# Troubleshooting Hacks¶

If the HTC Vive headset isn’t working at all:
• USB: Unplug the usb cable connecting the Headset with the computer you are using. Simply plug back in - in case another port is used, he drivers are newly chosen by Windows.
• Restart SteamVR: Click the SteamVR drop-down menu, select Settings. Choose the Developer tab, scroll to the bottom and click Reboot Vive Headset.
• Restart Steam: This works in case Steam tried to update SteamVR and failed.

If there are problems with tracking:

• Make sure the lighthouses can both see each other and at least one of them can see the headset at any point in time.
• If controllers aren’t tracked make sure their batteries are charged. You can also sync them manually by right clicking on one of them in SteamVR.
• If the tracking is off or doesn’t work at all, try doing the SteamVR room setup.
If the position is not optimal:
• Open the SteamVR drop-down menu, click Run Room Setup.

## Unity¶

Unity sometimes displays unexpected behaviour contrary to what is coded and/or expected. First advise: Restart Unity - this may sound banal, but it would have saved our team at least an hour of debugging.

## Simulation¶

1. If gazebo fails to start server or they die unexpectedly:

Kill the gazebo server and restart it.

killall gzserver
killall gzclient


Another possible fix is to kill Roscore

killall roscore

2. In case Models could not be found - which is often the reason when simulations take forever to load:

Export the gazebo paths to the model: General Usage/Getting started/