[[WhydoCamelthrowsomanyNoClassDefFoundExceptiononstartup-WhydoCamelthrowsomanyNoClassDefFoundExceptiononstartup]]
= Why do Camel throw so many `NoClassDefFoundException` on startup?

Camel uses a runtime strategy to discover features while it starts up.
This is used to register components, languages, type converters, etc.

If you are using the uber .jar (the big camel.jar) with all the Camel
components in a single .jar filen, the this problem can typically
occur.
Especially the type converters is know to cause `NoClassDefFoundException`
in the log during startup. The reasons is that some of these type
converters rely on 3rd. party .jar files.

To remedy this either add the missing .jars to the classpath, or stop
using the big .jar and use the fine grained jars.

See also xref:how-do-i-use-a-big-uber-jar.adoc[How do I use a big (uber) JAR?]
