Thanks for your reply but Im not sure you offered anything new besides what I stated in my post. The run.bat which I dont touch or recommend anyone to touch uses relative paths and checks for system variables like %JAVA_HOME% and will return an error if its not found or set incorrectly (different kind of error). Maybe there is a way to ensure that the run.bat and the referenced file "nifi-env.bat" where the NIFI_ROOT is being set is taking care of whitesapces in the path. I tried different things like surrounding the "NIFI_ROOT" with double quotes where referenced but it did not help.