Dropdown menu appear behind the content. (DNN MinimalExtropy Skin)

You just upgraded your site to DNN6, and now your dropdown menu's appear behind the content. (MinimalExtropy Skin).

SOLUTION:

1. Goto: Portals >> _default >> Skins >> MinimalExtropy >> css
2. Open menu.css in text editor or Visual Studio
3. Search for the following line
   1. /* SUB Menu Normal */
      .mainMenu tr.mi{
          background-color:#F8FAFF;
          z-index: 1000;
          font-size: 11px;
          font-weight:bold;
          text-align:left;
          color:#375162;
          line-height:2em;
          text-transform:none;
   2. Change z-index: 1000; to z-index: 905;
   3. Save the file and restart your DNN website.