Error of it's dependency lib: slf4net

[zclmoon]

slf4net: Error initializing LoggerFactory. Defaulting to no-operation (NOP) logger implementation.

Application information:
Application domain: xxxx/kids/cms-2-xxxxx
Application path: xxxx\Helix.CMS
Machine name: xxxx

Exception information:
Exception type: TypeLoadException
Exception message: A null or zero length string does not represent a valid Type.

at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName)
at System.Type.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase)
at slf4net.ActivatorUtils.Instantiate[T](String typeName)
at slf4net.Resolvers.AppConfigFactoryResolver.CreateFactoryInstance(FactoryConfigurationElement factoryConfiguration)
at slf4net.Resolvers.AppConfigFactoryResolver.LoadConfiguration()
at slf4net.LoggerFactory.PerformInitialization()

[adrianluisgonzalez]

Can you provide a simple reproducer?