https://bz.apache.org/bugzilla/show_bug.cgi?id=65884
--- Comment #9 from Felix Schumacher <felix.schumac...@internetallee.de> --- I believe, that the NPE is a result from fixing Bug 63620 and can (at least on my machine) be ignored. It should not interfere any further. The ClassNotFoundException should be unrelated to this (nor 63620) and might be a conflicting or missing commons-collections (3 or 4) jar. Look for commons-collections*.jar in the lib folder (and its subfolders), are there duplicate entries? You should find commons-collections-3.2.2.jar and commons-collections4-4.4.jar directly under lib. Which OS and JDK are you testing with? If you are willing to try, I can provide you with a JMeter version without the fixes for 63620. -- You are receiving this mail because: You are the assignee for the bug.