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<json_spirit::Pair_impl<json_spirit::Config_vector<std::string> >, std::allocator<json_spirit::Pair_impl<json_spirit::Config_vector<std::string> > > >'
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 <hex data> [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.
