Configuration error in the Logging Application Block
As you can expect the application block is driven by a configuration section in the config files.
Today I got an error along these lines - "The configuration for TraceListener named Trace Listener A is missing from configuration."
I've briefly checked the configuration file and didn't find a problem in my source or listener.
What I did find strange was that I did not used to so called Trace Listener A in the bit of code I was running but another trace listener.
A closer look at the config file (through the skilled eyes of Ben here) revealed the problem - another source had that listener configured but had a leading space in its name.
I did not expect the application block to check the validity of the links between other sources and their listeners, but assumed it only looked at the one it is asked to use in any given time, evidneyly it does validate the entire section.