错误详情：Error: got unexpected status: BAD_REQUEST – error validating channel creation transaction for new channel ‘mychannel’, could not succesfully apply update to template configuration: error authorizing update: error validating DeltaSet: policy for [Group] /Channel/Application not satisfied: implicit policy evaluation failed - 0 sub-policies were satisfied, but this policy requires 1 of the ‘Admins’ sub-policies to be satisfied
原因可能是已经存在一个channel
解决：
cd ~/go/src/github.com/hyperledger/fabric/scripts/fabric-samples/first-network/
./byfn.sh -m down
