Could be that you have duplicate jar files with different versions in your userlib directory, check for this and remove the older version.
My first guess is also always duplicate/missing jars.
The nosuchmethod error usually is triggered when you call for a function that isn't defined (so the options above). It could also be 'undefined' for the given parameter... so it expects a bytearrayoutputstream, but gets a null/empty object. So can you confirm that the function actually gets any input before triggering the error?