Mandatory package installation

when Mandatory package installation on client - select/cancel package reduces to closing client whithout any error Nothing's in log-file. ERP.8 SP 20 Who fixed? THKS

Maybe I'm misunderstanding but this isn't an error. There's a mandatory package - that means you HAVE to have it (It's mandatory because CNC have made it so - presumably because there's a good reason).
If you decline to take it by cancelling then you're declining the JDE software (period - mandatory means old versions are no longer supported).
So if you cancel it won't run - no problem there.

If you mean JDE fails to start even if you accept the package then I'd suggest you look at access to the deployment server from the workstation at the OS/file system level.