I am creating an altcoin.

I modified some parameters in chainparams.cpp after which after I recompile I get the error under, can anybody assist me with that? How ought to I repair this error?

BTW,I already have new genesis block hash,however the error appeared on the finish.

key.cpp:238: bool CKey::Signal(const uint256&, std::vector&, bool, uint32_t) const: Assertion `ret’ failed.
core has been dump