Electrs and Bitcoin Knots

StartOS Support
1

I am trying to update Elevtrs, it keeps switching from starting to running. The logs show this message:

2026-08-01T00:06:12-05:00 Caused by:
2026-08-01T00:06:12-05:00 0: bitcoind RPC polling failed
2026-08-01T00:06:12-05:00 1: daemon not available
2026-08-01T00:06:12-05:00 2: JSON-RPC error: transport error: unexpected HTTP code: 401

What should I do?

Thanks, KJ

2

I switched to Fulcrum after having the same issues. AI suggested reinstalling it, but then I couldn´t even find Electrs in Start9 or Community registry anymore. The resyncing of Fulcrumtook three days, though. Sparrow connected right away with no settings changed. Fulcrum runs fine.

3

Hi there

I assume you are still on StartOS v0351? Is that correct?

If yes then 401 is an auth error — Electrs is reaching your Bitcoin node fine but getting rejected on the RPC login, so its credentials are out of sync with the node rather than it being a sync issue.

Try this order:

  1. Make sure your Bitcoin node (Knots) is fully started and healthy first — not mid-restart.

  2. Stop Electrs.

  3. Open your Bitcoin node config and hit Save, then open Electrs config and hit Save. This re-wires the RPC credentials between them.

  4. Start Electrs again.

If you switched from Core to Knots recently, that save step on both is usually what clears it. Let me know your StartOS version (0.3.5.x or 0.4.0) if it persists and we’ll dig further.

4

Thanks for replying. After reviewing several posts from people who had the same issue, I learned that hitting the Save button on the Bitcoin node config and the Electrs config immediately solved the problem.

Thanks again!

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5

Thanks so much for responding. Prior to receiving your message I found a post making the same recommendation you gave and it worked. Thanks again for the prompt reply.

1 Like