It's a bit complicated, but does anyone else have access besides you?
If so, is the error the same for others who have access?
I don't think we'll be able to help you much here, only Meraki support will.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.