I added the code
.ux-menu-sub {z-index:30000!important;}
in the following files (delivered by ARI Soft)
menu.fix.css
menu.ie.min.css
menu.min.css
but nothing changed. The error is still there

None of these files contain the CSS rule. You can see it if try load them into a browser:

www.hasborn.de/modules/mod_ariextmenu/mod_ariextmenu/js/css/menu.fix.css

www.hasborn.de/modules/mod_ariextmenu/mod_ariextmenu/js/css/menu.min.css

BTW, we wrote add the CSS rule to "CSS Styles" parameter in module settings. We don't suggest add it to CSS files:



Regards,
ARI Soft

Thanks. I found the ccs rules in modul settings, added the code and it solved the problem.

Sorry, there is still another problem, when the main-menu uses more than one line. Now the submenu-items are shown, but when you move the cursor from mainmenu-item to the submenu-item, the submenu disappears. When you try this 3 or 4 times and move the cursor very slowly, then you can select the submenu item.
Do you have any idea, how to solve this problem. I have attached a copy of my module settings.
You can test it on www.hasborn.de

Try to add the following CSS rule to "CSS Styles" parameter in module settings:

.ux-menu UL.ux-menu-sub{margin-top:-1px;}

Regards,
ARI Soft

Thanks, this solved the problem