By the looks of your screenshot, you are using Premiere Elements 11. On what computer operating system is it running?
Is your issue one where "it worked before but not now" or "it never worked before"?
Some many questions, let us start with the usual drill...
a. How much installed and available RAM; how much computer hard drive space? Did you install the program to the default location? If you are using a Mac computer, do you have Adobe Premiere Elements 11 Editor from the Mac App Store or Premiere Elements 11 from Adobe?
b. Do you have the latest version of QuickTime installed on your computer?
c. Are you running the program Run As Administrator and from a User Account with Administrative Privileges?
d. What happens if you delete the Adobe Premiere Elements Prefs file or the 11.0 Folder in which it exists?
For Premiere Elements 11 Windows, see
Local Disk C
and in the 11.0 Folder is the Adobe Premiere Elements Prefs file that you delete. Make sure to be working with Folder Option Show Hidden Files, Folders, and Drives active so that you can see the complete path.
Please review to decide what is applicable to your situation and supply the details necessary for us to plan supplemental troubleshooting strategy if necessary.