Before using the free Library Expert Pro, you need to get and specify the Expert Key.
1. Login at www.PCBLibraries.com
2. If you do not have a key, click this button:
3. When you have an Expert Key, you will see something like this:
4. Select a CAD format you want to use. You can change to any CAD format once
5. Start the Library Expert Pro, and go to "Help" > "Cloud Key Activation", then enter your Email and Expert Key as provided to you on PCBLibraries.com, and click "Save".