Nokia X6-00 - Manual (Page 198)

Q: Why do I get the error message Expired certificate or Certificate not valid
yet when I am installing a downloaded application?
A: If Expired certificate or Certificate not valid yet is displayed, even if the
certificate should be valid, check that the current date and time in your device are
correct. You may have skipped the setting of date and time when starting the device
for the first time, or the mobile network may have failed to update these settings
to your device. To resolve this, select Menu
>
Settings and Phone
>
Phone
mgmt. > Factory settings . Restore the factory settings, and when the device
restarts, set the correct date and time.
198 Troubleshooting
© 2009 Nokia. All rights reserved. 198