Error Messages in Nokia S60, while installing an application
There are various error message that you may face while installing any application on you Nokia mobile. I am summarizing theme here with their actual meaning.

Certificate error. Contact the application supplier
You may have tried installing unsigned application. Note that signing is mandatory S60 3rd Edition. You can use self-signed certificate or developer certificate from Symbian Signed to sign your application.

Unable to install. Constrained by the certificate.
This message pops up when you attempt to install developer certificate in the unsupported device. The developer certificate from Symbian Signed can only be used in a limited number of devices. Remember that you have to send your IMEIs to Symbian Signed when requesting certificate. You cannot use the certificate in other devices that is not in your IMEIs list.

Required application access not granted.
Check that your certificate can be used to sign all capabilities needed by your application. For example, if you use self-signed certificate, you can only sign basic set capabilities, i.e. NetworkServices, ReadUserData, WriteUserData, LocalServices and UserEnvironment. If your application requires one of the extended capabilities, for example SwEvent, you cannot sign it with self-signed certificate. In this case, apply for developer certificates from Symbian Signed.

Unable to install a protected application from an untrusted supplier.
If you use self-signed certificate, make sure that your application uses unprotected UID, i.e. 0xA0000000 – 0xAFFFFFFF. If you use protected UID (0×20000000 – 0x2FFFFFFF) or legacy UID (0×10000000 – 0x1FFFFFFF), you will get this message.

Unable to install.
This message may come up when your installation file (.sis/.sisx) copies files to other application’s private folder, i.e. \private\sid. Note that Symbian 9 introduces data caging concept, it means you don’t have access to other application’s private folder.

@Madhu, I am extremely sorry since i am unable to help you this time. During my RNDs for installing new application on my old Nokia mobile I found some errors. I understood some of them and solved the issue. I collected their description from net and posted here. So it can help other. I am really novice to do such things.
I’ll suggest you to visit stackoverflow.com
i am using nokia 6700 slide,i am unable to hack my phone i have tried these methods
using hello carbide and explore and installserver
in this method i am not getting options
after selecting menu1 in hello carbide ,the hellocarbide is automatically exiting
(in this process actually one should oopen hello carbide and select options and then click on menu1 and select “yes” option
but i am not getting yes option
method 2:using
cert hack installer and certupdater
when i am in installing certhackinstaller,mobile is showing an error message “unable to install protected application from
an untrusted supplier
method3:
when i am using secman when i am opening it is welcome to secman and then i am clicking on ok then the app automatically exiting
method4:
when i am using xstevedore and then connecting to internet in xtevedore but no response in xstevedore
please help me
please help me my email.ID is madhu131313@gmail.com il reply u very fast
i am wworking on this for one month
my imei number is 353390041699412