MetaQueries plugin fail Grafana

Hi there,

We have a Grafana interface linked to openHistorian installed on a VM with demo devices. One of our distributors who have visitor access to the Grafana keeps receiving the error: MetaQueries plugin failed, Error: Failed to fetch Instantiating (as can be seen from the below image)

I do not get such as error from my office or home PC, so not sure why they are getting that error. Appreciate if anyone has a suggestion to rectify the issue.

Thanks,
Jalil

Could this URL be blocked by client firewall?