It seems as if stashcoin crashes too easily. It looks like it's using a very old fork of the Bitcoin source.
This is what happens when you call an un-supported/invalid RPC method:
terminate called after throwing an instance of 'std::vector >, std::allocator > > >'
Or when you call submitblock incorrectly:
terminate called after throwing an instance of 'std::ios_base::failure'
what(): CDataStream::read() : end of data
terminate called after throwing an instance of 'std::runtime_error'
what(): submitblock [optional-params-obj]
[optional-params-obj] parameter is currently ignored.
Attempts to submit new block to network.
See https://en.bitcoin.it/wiki/BIP_0022 for full specification.
You are correct, it's forked from bitcoin 8.5. I'm updating StashCoin to Bitcoin 9.0.0, I just have been busy with my offline life.