We have been running a private ethereum network for a couple of months.

Today we tried to add a new node to the network. When the node was synchronizing, (after 3-4 hours) it stopped with the following message :

5a0e number=847268 hash=0000...0000 allowance=847268 WARN [03-23|15:11:45] Synchronization failed dropping peer 5a0e err="retrieved ancestor invalid"

We tried it again by starting from scratch (deleting all retrieved chain) and the same problem appeared again at the same number=847268.

I will appreciate your help on resolving this issue.


1 Answer 1


I had the same problem but solved it in the following way.

  1. Go to your chaindata directory like "/home/user/.ethereum/testnet/geth/chaindata"

  2. Delete some of the recent ldb files and .log file. ( I've deleted 10 recent files.)

  • 1
    Got Fatal: Error starting protocol stack: missing block number for head header hash after doing this. Nov 13, 2017 at 19:30

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