We are able to catch all exceptions and handle them, if possible. Sometimes it is not possible to deal with all scenarios and therefore, we must introduce a logging mechanism to our application in order to collect information that can help to fix a bug.
Logging is more complicated in Silverlight than in a normal client or web application:
We cannot write to files directly
The isolated storage has only limited space, but we can ask the user for more
The application is running client side, the connection to a logging server can fail, or the server might not be available
The logging information must be persistent
Only a few frameworks for logging exist that also work together with Silverlight
At the moment, there is only one open source library for logging, which is the Silverlight port of the Enterprise Application Framework.