Hello,

my extension whose jar I add to the lib\ext directory overwrites an existing JMeter class. This works well in most cases, as the name of my extension begins with an "A" and comes first in the classpath before the other JMeter lib\ext jars.

Now I had the case of one system where this was not working and I checked the classpath and indeed, the order was not alphabetically.
NewDriver uses File.listFiles which does not guarantee a specific order!

Therefore my request would be to add the line 
Arrays.sort(libJars); 
to myDriver.java line 100.