Issues with certificates occur when installing applications on Nokia mobile phones. The problem is solved by disabling them or contacting the manufacturer's contact center.
Instructions
Step 1
Go to the Nokia 5800 mobile phone menu and go to the application manager. Open the functions and run the settings, set the value to "All" in the program settings and apply the "Disabled" property to check certificates. This is relevant in cases where the device generates an error related to an unsupported application or just an error in the certificate itself.
Step 2
If the message “Certificate expired” appears on your Nokia 5800 mobile device and the application does not require a signature (there is an updated certificate), go to the date and time settings menu, change the value six months ago. Install the program on your phone again, after removing it, if it still remains, then set the correct date and time.
Step 3
If you encounter problems with the installation of programs with the *.sis extension, install the version of the program designed for the Symbian 9.1 operating system. If this is available in your case, in the application manager menu, repeat the steps described in the first paragraph on disabling certificates. If that doesn't help, set the date and time back one year. This also applies in cases where you receive a message about an unsupported application, an error in the certificate, or a corruption in the installation file.
Step 4
To solve problems with certificates, use the simplest solution - reset your Nokia 5800 mobile phone to factory settings. This is done not from the mobile phone menu, but in standby mode by entering the combination * # 7370 #. The unlock code after that will be 12345.
Step 5
Please note that this action will delete all files, contacts, and other custom items from your mobile device, so it's best to back up your data on your computer in advance by pairing your device in sync mode.
