Sorry for the late reply. The validation error can happen if ONTAPi(http) is not enabled on the 7-mode system. However, OneCollect does collect through SSH as well. So the ssh commands woud work if you proceed with the collection in spite of the validation error.
If you would want to enable collection through ONTAPi (zapi) below options need to be set on 7-mode.
options httpd.enable on
options httpd.admin.enable on