The messenger service Whatsapp fixed a significant disruption after more than an hour on Tuesday morning.
This occurred all over the world, and within a very short time the service received 70,000 reports.
The parent company Meta confirmed that the breakdown has now been repaired.
"We have fixed the problem and apologize for any inconvenience," a spokesman for WhatsApp's parent company Meta told AFP.
The website Downdetector, which collects reports of disruptions in online services, saw a significant increase in reports about Whatsapp from around 9 a.m.
The complaints piled up in the online networks.
The disruption affects users of both Android smartphones and iPhones from Apple.
Around shortly after 10:30 a.m., the app worked again for many users.
Users of the messenger service had also reported on Twitter and other channels that they could no longer send messages.
Many also reported a failure of the Whatsapp platform on the Alle disturbances.de portal.
The reason for the disruption was initially unknown.
In an email, a Meta spokesman said the problem was known within the group.
Disruptions have been reported in the UK, India, the United Arab Emirates and Hong Kong.
A year ago there was also a large-scale disruption, causing many users to migrate to competitors such as Signal and Telegram.