Zcashd v5.1.0 wallet.cpp:4422 ... Assertion 'uResutlHeight = rewindHeight' failed

Hi guys!

I installed zcashd v5.1.0 on Linux Debian and It synchronized to 98%, now I have this error message when I try to run it: "zcashd: wallet/wallet.cpp:4422: int CWallet::ScanForWallettransactions(CBLockIndex *, bool, bool): Assertion ‘uResutlHeight = rewindHeight’ failed.

Can someone help me?

Thanks, Ale


Thank you for the report. Is it possible to update to v5.2.0? This might require a -reindex otherwise to resolve.

Hi mdr0id!

How can I specify -reindex options? to zcashd or zcash-cli command?

Thanks, Ale

Please use: zcashd -reindex from command line. Please be aware this will cause the node to reindex, which will take quite a bit of time depending on your internet and machine resources.

After zcashd -reindex I have to download chain yet! No I have 0% chain… It’s horrible!!


What do you say about

The same problem is easily reproducible.

Is it still worth solving by constantly calling -reindex and -rescan?

The alternative is to upgrade to v5.2.0. I personally run multiple nodes and many more for other internal operational reasons, so I understand your frustrations.

Sometimes the reindex and rescan are unfortunately part of getting the node back to a graceful state. In the future we hope to reduce the need to use this.

I am a noob on 5.2.0, and I have this problem. :confounded:

If I understand you correctly you have built or downloaded zcashd v5.2.0 on a linux system and on the first sync you saw the above error?

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Yes. I followed the binary install instructions:

What system resources(e.g. CPU, RAM, DISK, cloud or baremetal machine) are on the computer you are using to sync?

The machine specs were given in the original post:

except to mention that it’s running in a Proxmox VM.

Im syncing a fresh node on hp amd turion ii dual x2 with 6GB + lotta swap, letya know

If it is possible to increase your RAM on the VM to 16GB and try again?

I’ll get back to you. I have a long-running job that I don’t want to interrupt.

There was one “hiccup” that I suspect was caused by my running a Proxmox backup on the VM while the Zcash download was running. Zcash aborted at the time when Proxmox issued a “fsfreeze” via the qemu-guest-agent, which is installed in the Linux guest.

I restarted the Zcash daemon with the addition of -rescan and -reindex. It’s now at 2202-07-20 and coming along nicely.

I will update you when it either completes or fails.


WOOT! :tada: :zcash:
I have not personally used Proxmox but did check it out a bit for VM tooling. It (zcashd) “should” sync, but you might notice a slow down when it gets to more recent blocks from the past couple of months due to transaction load.
We have been able to sync newer ARM boards(e.g. RPi 4 and Odroid 8GB boards), but sometimes you will run into issues with swap space FWIW.

The blockchain successfully downloaded. I shut down zcashd, and I am taking a backup.
Thanks. Problem solved.

Be mindful that chains created with a zcash.conf containing:


Will differ from the default zcash.conf. Chains created from these flags should be considered a completely different backup as it will require a node to rescan etc.

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