invite user to group, error permission denied

[M Fariz Wisnu Prananda]

I'm using xena, and I created a group with other users. And when I invite another user with tinode id, get error like this
{Message:ctrl:{id:"INVITE-USER-usrm_1YLPxIZP8"  topic:"grp64lfBT3XjZQ"  code:403  text:"permission denied"} 

with tinode grpc like this 
{
    "set": {
        "topic": " grp64lfBT3XjZQ  ",
        "query": {
            "sub": {
                "user_id": " usrm_1YLPxIZP8  ",
                "mode": "JRWP"
            }
        }
    }
}

why is this happening?

[Gene]

Please show the complete logs.