While Using Chaincode policy flag getting error as Invalid Signs

[AmeerRiyaz]

Hi all , I have used the flag as mentioned in the help functionality of minifab "./minifab approve -y "OR ("org0-example-com.member", "org1-example-com.member")" " but i am facing an error of Invalid signatures If any one can guide me with this issuse will be helpful Thanks and Regards Ameer