Tons of JARs are in the classpath of Fiji. Multiple JARs might contain the same class definition.
In order to know which JAR is the one hosting the version Fiji is actually using (this is determined by the order those JARs are found in the CLASSPATH), you can use this handy function from within Fiji.
Start Fiji – hit ctrl+L or cmd+L on your keyboard – type ‘jar’ in the search field – start ‘Find jar for class’ and type the name of the class + the entire package information as shown below – hit ‘Ok’ – done!
