In FW we use a Lets certificate that is automatically generated and renewed by the FW, but this month it has not renewed.
We tried to manually renew but returned the attached error. As a workaround we are using our Wildcard certificate at WAF.
What could be causing this error and what can I do to resolve it?
As mentioned by Gernot, make sure the UTM is updated to 9.707.
Also, check the letsencrypt.log and make sure the UTM is able to reach the following URLs https://letsencrypt.status.io/
However on Jul 14 Lets Encrypt had an issue with one of the URLs so most likely it was related to that https://letsencrypt.status.io/pages/history/55957a99e800baa4470002da