INVALID_KEY

One of the keys used in this transaction is not valid.

[Error Code: 1008] error caused by: 1 error occurred: * transaction verification failed: [Error Code: 1006] invalid proposal key: public key 0 on account 8b903e5747634496 does not have a valid signature: [Error Code: 1008] invalid payload signature: public key 0 on account 87e2f3348cf2788e does not have a valid signature: signature is not vali