I can't authorize SketchUp because the License menu is grayed out.

      NOTICE: SketchUp 2015 is here! When you look at this Knowledge Center article, be sure to pick "SketchUp 2015" from the red box above to see the 2015 version of that content. If there is no version picker, this content applies to all versions of SketchUp.

This can happen if SketchUp Make is installed as opposed to SketchUp Pro. To correct this issue, we suggest downloading and installing the SketchUp Pro trial. For more assistance, click here.

If you continue to encounter an issue, you may want to consider uninstalling SketchUp. For more information about uninstalling, please click here.