Help! Error when release funds invoking MetaMas,

Hi there, we are building a escrow service on Ethereum on ERC20 tokens, i.e., it first deposits funds/tokens to a smart contract, and then invoke metamask to release the funds from smart contract, however, when doing two release funds in a row, metamask internal JSON-rpc error (sorry, i am new to the forum, couldn’t upload image for now.).

Could someone point me to the right direction on how to solve this problem?

Thanks in advance.