The new feature called “Gatekeeper” is designed to make it hard for you to install software that has not been purchased from the Apple store. Instead of opening the “launch.jnlp” file that installs JDLab2You, it will tell you that the software is “from an unidentified developer,” that it cannot be opened, and gives you no further options.
Fortunately, there is a work-around. Although Apple does not allow you to directly install JDLab2You, it does save the installation file to your hard drive so that you can install it manually. Here are the steps:
1. After you attempt to install JDLab2You and receive the error message, close your browser and open your Downloads folder. Do this by clicking Go on your finder menu, then click Downloads.
2. Look for the file “launch.jnlp” – it is the JDLab2You installation file you just downloaded.
3. In Finder, control-click or right click on “launch.jnlp” and choose Open. A dialog box will pop up and you will click Open again.
4. Enter your user name and password if required.
5. At this point the installation will proceed as normal. Do this by clicking Go on your finder menu, then click Downloads.