#2 Apr 24, 2019 21:29
The error is because that particular PHP instance executing on that particular domain is not able to communicate with our server for some reason that is external to our server.
The fact that the error message is not displaying all the time is normal. When there is an error b2evolution will wait for some time between 10 and 60 minutes before retrying. When it doesn't try, there is no error message.