Invalid block XX: unknown ancestor while restoring the chain - private blockchain

Looking at the image, it seems to me you are importing the backup of a private network to a node initializated with the Mainnet.

I suspect this because:

• geth says ChainID is 1, so Mainnet
• the import process seems to stop with the very first block and the error is unknown ancestor, so it don't know the genesis block
• your block #1 hash is not the hash of the first block of the Mainnet, that is 0x88e96d4537bea4d9c05d12549907b32561d3bf31f45aae734cdc119f13406cb6

If this is the case, just remove the geth database:

$ geth removedb

and init again with the correct genesis block:

$ geth --networkid [yourNetworkID] init [yourGenesisFile.json]

If you don't remember the networkID, you should be able to read it in the genesis file.