Unlike iOS of the same era, the Nokia C7 does not require a reboot to change themes. When you select a new theme from Settings > Themes , the OS reloads the UI shell (called "AknIconUtils") in the background. You will see a quick "Please wait" spinner, and then the new theme is applied instantly.
| Problem | Symptoms | Quick Fix | | :--- | :--- | :--- | | | During installation, the phone warns that the "certificate has expired." | Temporarily set your phone's date back by a few months or a year . Install the theme, then set the correct date back. This works because the digital signature has a set validity period in the past. | | Certificate Error / Not trusted | The phone refuses to install the theme, citing a general certificate issue. | Go to: Menu > Applications > Settings (or Tools ) > App. Manager > Options > Settings . Then, change "Software installation" to "All" and "Online certificate check" to "Off" . | | Theme Not Showing Up | The installation seemed to succeed, but you can't find the new theme to activate it. | Navigate to: Menu > Settings > Themes > General . The newly installed theme will be listed here along with your default themes. Simply select it to apply it. | | Theme Won't Delete | You try to uninstall a theme, but it remains or gives an error. | If the standard uninstall fails, try using a third-party application like QQ手机管家 (QQ Mobile Manager) or 360手机管家 (360 Mobile Manager) to force-remove the stubborn theme. | nokia c7 themes work