In general PuTTY tends to either work without problems or not work at all with a given configuration. However, there are some things that may help, and this document lists a few tricks to try. If none of these issues help, consider filing a bug report, but see the bug reporting hint page before doing so.
Unless separately noted these tips apply to all PuTTY for Symbian OS versions. Many of the tricks require a more advanced file manager application than the one shipped with the device. Remember also that directly manipulating files in the system directory can be dangerous and lead to problems, so proceed at your own risk and remember to back up your data!
Sometimes PuTTY may fail to start because the default configuration file is corrupted. The easiest fix is to delete the file. It is located in \system\apps\putty\defaults, on the drive where PuTTY was installed (c: for internal memory, d: for memory card on the 9200 series, e: for memory card on Series 60).
If this helps, and you can figure out what you did when the configuration file got corrupted, let us know.
If PuTTY starts and a network connection is set up, but the SSH connection does not open (no username or password prompt), there may be a problem in the access point or dialup server you use. Some operators, for example, disable SSH access from some of their GPRS access points. If this happens, try using a different access point (GPRS, Series 60) or dialup server (CSD or HSCSD).
Note that PuTTY needs an "internet" access point to work. Many operators have different GPRS access points for WAP use, but those can only be used to connect to the operators' WAP gateway. Those access points won't work. If unsure, ask your operator what access point to use for internet connections from a PC.
If the SSH connection still fails, try using the phone as a modem and connecting from a PC using the same dialup server or GPRS access point. If that fails, the problem is most likely that the access point or dialup server does not let SSH traffic through, and there is nothing PuTTY can do about it.
PuTTY for Symbian OS versions 1.2 and above support logging to a file. The log can contain useful information on the connection, and help you determine what the problem is. It is also useful to attach a log file to bug reports, but please check first that the log does not contain secrets such as passwords.
Logging can be enabled as follows:
The log files are regular text files, and can be viewed with Notepad or other text editor. Most file manager applications can even view them in the device itself.