UK operator O2 said its 4G network was not fully restored until early Friday morning.
In addition to O2 and Softbank, Ericsson later admitted that the problem also affected business partners from 11 countries.
According to the data, Ericsson is not the first company to be affected by the risk of expiring certificates. Back in 2013,XboxLive and Azure suffered a downtime because of an expired certificate, and in 2015, some Mac App Store users were forced to delete and reinstall certificates to verify that the application was expired. This year, an expired certificate made Oculus River unusable unless the system time was modified.