Wallet/wallet.cpp:648: void CWallet::IncrementNoteWitnesses(const CBlockIndex*, const CBlock*, ZCIncrementalMerkleTree): Assertion `nWitnessCacheSize >= nd->witnesses.size()' failed."

Technology zcashd client
4

There was a black out and my ubuntu running on virtualbox mining zcash shut down under power loss. when i reboot and try to start up daemon, it gave me this error again zcashd: wallet/wallet.cpp:702: void CWallet::IncrementNoteWitnesses(const CBlockIndex*, const CBlock*, ZCIncrementalMerkleTree&): Assertion `nd->witnesses.size() == 0’ failed.

any ideas or do i need to recompile and restart from zero again?