# Beware updating Electrs if not bought into SHA256 Chain
**URL:** https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746
**Category:** Discussion
**Tags:** services
**Created:** [September 19, 2026, 9:36am UTC](https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746 "2026-09-19T09:36:51Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@sovern](https://community.start9.com/u/sovern)
#### Post date: [September 19, 2026, 9:36am UTC](https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746/1 "2026-09-19T09:36:52Z")
If you upgrade Electrs now to 0.12 it only supports Core 31.. you can’t Downgrade and sideload downgrade doesn’t appear to work - so you will be left with little choice but to move to Fulcrum and commence index from beginning.. Would have been nice to know what this was a breaking change to knots dependency; but there you go.🫤
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### Author:  [@shurtenburt](https://community.start9.com/u/shurtenburt)
#### Post date: [September 23, 2026, 12:20pm UTC](https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746/3 "2026-09-23T12:20:24Z")
This is why you should read the release notes, before you do an update, especially in the situation with the chain split.
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### Author:  [@Rexter](https://community.start9.com/u/Rexter)
#### Post date: [September 23, 2026, 2:16pm UTC](https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746/4 "2026-09-23T14:16:06Z")
I’m not sure this is the expected behavior. I’d like to learn more about your pre-updata setup. What flavor and version of Bitcoin, and what version of Electrs were you on, before updating Electrs to 0.12?
Update: This is known behavior. Matt is going to strengthen the release notes about this, and make it so a downgrade is possible. For people who have already updated, if they want to stick with electrs they will need to uninstall, then reinstall at v11. Then never update to v12. I know this doesn’t solve your specific case. I’m sorry. But for future updaters, they will be able to downgrade back to v11, without re-indexing.
In your case, since you’ll need to re-index anyway I’d recommend switching to Fulcrum.
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### Author:  [@sovern](https://community.start9.com/u/sovern)
#### Post date: [September 24, 2026, 2:27am UTC](https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746/5 "2026-09-24T02:27:28Z")
hindsight is 20/20, Breaking Changes are not accidental. There is plenty of incentive out their to squash any challenge to Bitcoin’s capture.
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### Author:  [@Lou](https://community.start9.com/u/Lou)
#### Post date: [September 24, 2026, 4:24pm UTC](https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746/6 "2026-09-24T16:24:13Z")
Same here. Only noticed after I had already upgraded and I wasn’t able to downgrade either. I had to uninstall and reinstall vers 1.1 and wait for the reindex to finish before mempool would work. So, I’ve always used electrs, is fulcrum a better choice now and why?
Thanks.
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### Author:  [@Rexter](https://community.start9.com/u/Rexter)
#### Post date: [September 24, 2026, 4:46pm UTC](https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746/7 "2026-09-24T16:46:41Z")
Fulcrum is a better and faster indexer, especially for wallets that may have a long history. The only down side, it takes a little longer on the initial sync, and consumes more drive space. I’ve noticed a significant increase in wallet performance since switching to Fulcrum.
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### Author:  [@Rexter](https://community.start9.com/u/Rexter)
#### Post date: [September 24, 2026, 5:15pm UTC](https://community.start9.com/t/beware-updating-electrs-if-not-bought-into-sha256-chain/5746/8 "2026-09-24T17:15:59Z")
I think it has more to do with a specific feature in 31, that helps Electrs be a better indexer. I don’t think there is any reason a future version of Knots, or Knots Legacy cannot include the REST API in their implementation.
> **[Release v0.12.0 · romanz/electrs](https://github.com/romanz/electrs/releases/tag/v0.12.0)**
>
> Switch to bindex:
>
> requires Bitcoin Core 31+
> uses REST API server (-rest=1)
> new index format - requires reindexing!
>
>
> Fix server.features response format.
> Update transaction.id\_from\_pos argument pa...