This works with no issues when Middleware is installed on Windows but doesn't work when it's installed on Red Hat Linux
I have already set up LD_LIBRARY_PATH as explained in this note FRM-47700: "Failed To Start The JVM" After Upgrade To 12c Forms/Reports From Fusion Middleware 11gR2 (Doc ID 2345472.1) on Linux machine ( in .bash_profile and default.env files). After setting up LD_LIBRARY_PATH I don't see the error JVM failed to start but still can't launch the Debugger I have also specified debugger.jar path as a first entry in the CLASSPATH in default.env file
Please test to see if you can open the Builder Help. From the menu, About > Help Contents
Also, you mentioned setting values in default.env. Did you do it directly in the file or via Fusion Middleware Control (EM)? If you did not make changes via EM, your changes likely are not being seen. You must make changes via the web interface (EM). Also be sure you have allow_debug=true in the Web Configuration.