I opened a case yesterday for this issue. I'm also seeing the curl error 60 and "the certificate expired 5 days ago" if I go to the URL. Support doesn't seem to be on the same page. They're telling me it's my agent version.
Also have a support ticket opened regarding this. It looks like they did renew their cert (check the cert on the meraki dashboard https://n342.meraki.com/), but whatever system is hosting cf.meraki.com hasn't been updated with the new cert... this should be a very easy fix to apply the new cert - and considering its unusable right now I would think would be a priority, but I put the case in yesterday morning and still nothing.
This is correct for the dashboard, but they have not updated the systems hosting cf.meraki.com with the new cert... go to https://cf.meraki.com/cf/config, the cert is still the old one (as of now)