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Troubleshooting

Reporting a bug

Open an issue on GitHub and attach KSP.log, which is in the KSP folder. Prefixing the title with Bug: helps with triage.

The web UI does not open

JRTI's page is http://localhost:8080/ unless you changed the port. If the page is missing or shows another program's page, the port may already be used by another program.

JRTI usually warns you about this on screen when the game opens, and writes it to KSP.log. To fix it, pick another Port in JRTI's settings (Ctrl + Alt + F8), then restart the game.

If it works on the KSP computer but not from another device, use the network address shown at the bottom of the web UI instead of localhost, and check that the computer's firewall lets the game accept connections. On Windows, allow KSP_x64.exe through Windows Defender Firewall (Windows Security, Firewall & network protection, Allow an app through firewall, Allow another app), making sure the rule covers your network's Private profile. Or open the port from an administrator command prompt, replacing 8080 with your port:

netsh advfirewall firewall add rule name="JRTI" dir=in action=allow protocol=TCP localport=8080

Record stays off

JRTI found no working video encoder. Open its settings window in the game (Ctrl + Alt + F8): it says why and which encoders were found. See Recording for installing ffmpeg, or Linux and Proton on Linux.

Frame rate drops

  • Turn off integrations you do not need in the settings window, under Visual Mod Integrations. Parallax is off by default because it is expensive.
  • Open the performance overlay with Ctrl + Alt + F6, or the Diagnostics page in the web UI, to see per-camera frame times, GPU time and video memory.
  • Lower Max FPS or the render size in the settings window. Each camera render costs about as much as the game's own view.
  • Keep Spread camera renders across frames on, so cameras take turns instead of rendering together.

Known issues

  • macOS is not fully supported. A GPU async API used internally by this Unity version is unavailable on macOS, a legacy quirk inherited from KSP's Unity build. Streaming works through a synchronous readback that may stutter at higher framerates.
  • Performance with Parallax. Enabling the Parallax integration may cause significant frame-rate drops.