[Andy Blackburn]

My calendar app will not load since I updated to Lumia denim.
It still shows my appointments in the live tile but when I try to load the app it just returns me to the start screen. Any ideas how to fix this?

[dKp1977]

Yes, simply perform a soft reset:

Press and hold volume down and power button simultaneously for approximately 10 seconds. Release, once the phone vibrates and let it boot up as usual. Check time and date afterwards, as these get reset to the time and date the last OS or firmware update was applied. Change it if doesn't correct itself automatically.

[Andy Blackburn]

Thanks, for your response. I have already tried this without success. Any other ideas that won't involve a reinstall of the OS?

[apocacrux]

Yes, simply perform a soft reset:

Press and hold volume down and power button simultaneously for approximately 10 seconds.

Volume down is not a required button press. Just hold the power button, this has been the case since 8.1 update.