So I googled a bit about the problem, and it seems most of the time
it is caused by a corrupted blockchain, this can have multiple reasons,
maybe you had a power outake or a hardware problem like faulty ram.

For example:
https://github.com/bitcoin/bitcoin/issues/4125
https://github.com/bitcoin/bitcoin/issues/4064

Most of the time it gets fixed by running bitcoin with the "reindex" option,
that will take a long time and rebuilts the blockchain database.

You may try that by adding

to the bitcoin.conf, but remember to remove it afterwards, else
it does this everytime you start bitcoin.