Source: Click’n’Go (clickngo.com)

The error message states that the format expected for phone numbers is “+CCC.NNNNNNNNNNxEEEE, where C is the 1-3 digit country code, N is up to 14 digits, and E is the (optional) extension.”

It’s hard to know where to start discussing a message that includes such a geeky message. Maybe I’ll just let it speak for itself.