The NSW government's customer service app stopped working for several hours on Thursday, preventing people from checking into venues for COVID-19 contact-tracing.
It's the second time this year the Service NSW app and its COVID-Safe Check-in function have crashed.
People began complaining on social media that the app was not working about 2pm on Thursday.
"We're aware of an issue affecting multiple Service NSW transactions and services. We're working to resolve this ASAP and sincerely apologise for the inconvenience," a Service NSW account tweeted.
At 5.30pm, the problem was still not resolved.
Since January 1, venues including restaurants and cafes have been forced to use only the Service NSW app to facilitate check-ins.
The app earlier crashed for several hours on January 7.
The government revealed last week that about three quarters of the NSW population had downloaded the app.
