The -Djava.endorsed.dirs is no longer needed or supported. After Java 8 the JVM will not start if this option is included.
For Windows users, you can download and run the latest installer (184.108.40.20679+). This newer installer proactively removes the endorsed java option so you can use Java 9 whenever you are ready.
The alternative way is to manually remove the java option. In Windows, open the QIE Service Manager, and click the Startup tab. In the Arguments section remove the highlighted line below (which contains the -Djava.endorsed.dirs), then click Apply.
NOTE: It is very important that only -Djava.endorsed.dirs line is deleted. Also, make sure that each of the other arguments remains on their own line. It may be easier to copy all of the arguments out to a notepad remove the -Djava.endorsed.dirs line and then copy all of the other arguments back into the QIE Service Manager Arguments.
For Mac and Linux users, go to your QIE home directory and edit the start.sh file. Remove the line that contains the -Djava.endorsed.dirs. Save the file.