On August 16th, 2024, certificates on some deskphones expired, which prevented them from connecting to the RingCentral system.
Phones with outdated and invalid certificates that couldn't be remotely updated by RingCentral lost functionality, including the ability to make and receive calls.
To fix this issue, you’ll need to factory reset your phone and then set it up to work with RingCentral’s system.
Select the manufacturer for instructions on factory resetting your phone.
After factory resetting your phone, you’ll need to set it up again. On that page, choose your device, then Connecting to RingCentral, then scroll down to the manual set up instructions.
If the above steps don’t resolve the issue, and your phone still isn’t working, contact your service provider for assistance.