[tcxcardoso]

Just happened. Thing is JAVA also was just updated from its website, so I don't know if there is anything to do with it.

java.lang.ClassNotFoundException: org.jdownloader.update.launcher.JDLauncher
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.exe4j.runtime.LauncherEngine.launch(Unknown Source)
at com.exe4j.runtime.WinLauncher.main(Unknown Source)
at com.install4j.runtime.launcher.WinLauncher.main(Unknown Source)

That's the error I get when I try to load JD2.

[Jiaz]

There should be a JDownloader.jar.backup file in your JDownloader folder.
Rename it back to JDownloader.jar
Delete Core.jar and the tmp and update folders and start it Again
You can also download JDownloader.jar from

mega.nz/#!mctCnIhC!fNqx1UOf06cVB7h9Cis1Kk5J_tAGMTFsSQcuQ2FPfYw

[tcxcardoso]

Thank you! It worked!

[Jiaz]

Thanks for the feedback!

[jj0901]

This happened today. Startup Error

Can you help?

java.lang.ClassNotFoundException: org.jdownloader.update.launcher.JDLauncher
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.exe4j.runtime.LauncherEngine.launch(Unknown Source)
at com.exe4j.runtime.WinLauncher.main(Unknown Source)
at com.install4j.runtime.launcher.WinLauncher.main(Unknown Source)

[Jiaz]

see https://support.jdownloader.org/Know...r-installation

[jj0901]

Originally Posted by Jiaz

see **External links are only visible to Support Staff**...

Unfortunately it did not help. However, I re-downloaded JDownloader 2 and the problem was fixed. Thank you though for your immediate response.

[Jiaz]

@jj0901: can you please explain what did not work? I'm asking because this method is literally the same as installing JDownloader again. You just have to delete the Core.jar file, the update and tmp folder AND either download JDownloader.jar and replace existing one or restore JDownloader.jar from existing backup file.

[kovace]

I don't know for the other guy but for me work like charm (just rename backup to jar). I guess when close JD have some update and I shutdown my pc directly. Was late for work. Well good to know for next time(go to be a next for sure)