Getting error messages about certificate errors when installing PuTTY? Read on!
PuTTY for S60 third edition is currently a self-signed application. This means that while it works without issues once installed, the application installer can either display warnings or refuse to run completely. Since installing self-signed applications can be risky, you should always check the PGP signature to ensure you are installing a real PuTTY package. However, some phones may require additional work to get PuTTY installed.
Some, or possibly all, Nokia E-series phones refuse to install self-signed applications by default. This can be fixed by changing installer settings as follows. From the device menu, open:
Tools / App. mgr. / Options / Settings
Then set "Software installation" to "All". The default on most E-series phones is "Signed only". The names will be different in devices using a different language but the same setting should be present.
Warning! This will enable installing all self-signed applications, including possible malware, so be careful what you install and don't accept installation packages from an unknown source. The installer will also list the capabilities the application needs, and you should check that those make sense. For example, it's natural that PuTTY needs network access, but if a simple game requires it something may be wrong.