any times you might faced a common problem while installing Symbian applications you've downloaded from other than official sites, for exp any modded or cracked software. Such application show you Certificate error or autontication failed etc and preventing to install application. How to resolve this issue to use your favorite cracked or modde app? Here a simple way to got this.

Which Mobile Phones Need Certificates: Not all mobiles need cer. when they install third party softwares. Only those whose system is Symbian S60v3, S60v5, Symbian^3 and Symbian UIQ3.0 need cer. and others not need certificates. All unhacked phone specially need this and when you've certificate for your phone you don't need to hack your phone and take any risk. Below all method, instructions and applications are compatible with all Symbian S60v3, S60v5, Symbian^3 and Symbian UIQ3.0 phones.