What computer operating system is your Premiere Elements 12 running on?
Have you ever opened the program and created a project with it? In other words, is this a "it worked before but not now" or "it never worked before" issue?
1. Determine if the problem exists with and without the antivirus and firewall(s) disabled.
2. Right click the desktop icon, then from the drop down menu, select, click on, apply Run As Administrator.
3. Do you have the latest version of QuickTime installed on the computer with Premiere Elements?
4. Have you installed and are running the program in a User Account with Administrative Privileges?
Let us start here and then decide what next.