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Troubleshooting

Can’t connect to the debugging port

Section titled “Can’t connect to the debugging port”
  • Confirm the Chrome instance launched from the generated command is still running.
  • Double-check the port in the popup matches --remote-debugging-port in the command you ran.
  • Only one process can bind a given port - generate a new one if it’s already taken.

No tabs show up after Fetch tabs

Section titled “No tabs show up after Fetch tabs”
  • The tab list only includes page and iframe types - background/service-worker targets are filtered out.
  • Open at least one regular tab in the remote instance (or use New tab), then fetch again.

New tab fails to create

Section titled “New tab fails to create”
  • Check the inline error under the URL field - it surfaces either an extension error or whatever the remote instance’s /json/new endpoint reported.
  • Make sure the port is still valid (1–65535) and the remote instance is still reachable.

Network tab stays empty after enabling

Section titled “Network tab stays empty after enabling”
  • Make sure the attached page actually makes HTTP(S) requests after you flip the switch - requests that already completed before enabling won’t appear retroactively.
  • WebSocket traffic is intentionally excluded from this tab.

Can’t find the custom headers editor

Section titled “Can’t find the custom headers editor”

Open the Network tab and turn on Enable network logging. The Add custom headers or Edit custom headers button appears beside the toggle. Custom headers are managed there rather than in Presets.

Checking whether custom headers were cleared

Section titled “Checking whether custom headers were cleared”
  • Closing the editor preserves its draft. Close it, then use Clear headers in the Network toolbar to remove the applied header set and reset both editor modes.
  • After clearing, Add custom headers should open with one blank row and empty JSON. If an older editor still appears, reload the updated extension and refresh the inspector page.
  • Inspect a new request after clearing. Earlier captured requests retain the headers they were sent with.

Execute JavaScript returns “unparsable object”

Section titled “Execute JavaScript returns “unparsable object””

This is expected for values JSON can’t represent cleanly - functions, Map/Set, NodeList, NaN/Infinity. Convert the value to a plain object/array/string before returning it.

Keyboard input isn’t reaching the remote page

Section titled “Keyboard input isn’t reaching the remote page”

Make sure your mouse is actually hovering the screencast frame - keyboard forwarding is gated on hover, not on having clicked into it, and a green ring around the frame confirms it’s active.