[Solved]-Cannot load or find main class, works in command line but not in IDE's-eclipse

if ./gradlew clean build gives no errors, the resulting jar can be run successfully and your gradle wrapper is fine (see question comments for more info), maybe reimporting the project to eclipse (as a gradle project, -> buildship) may result in finding the main class

my thoughts: you ensured that your gradle build is working and other gradle projects within the same worksace are functional too. then the next logical step is to work with a fresh copy of your project: re-import it.

after closing eclipse delete all eclipse related files (.settings, bin, .classpath, .project) as well as the run configuration you used to start the application. make sure you back it up or know all infos to recreate it (vm args, environment vars for your run config).

i know this is an invasive step, but if you say other fresh eclipse projects work, why not make your project a fresh one too?