You need to close an open project first before you can open another project. You can't have multiple projects open at the same time.
Yes, I realize that. As I said:
When this happens I also am unable to close the current project or even exit from Premiere Pro.
I found a workaround in case anyone else encounters this problem: simply run Premiere Pro as Administrator. In the Start menu right-click on Premiere Pro and do Run as Administrator. (This is for Windows.) Unfortunately, this causes a UAC dialog every time you run PPro but at least it works.
To simplify the process for the future right-click and do Pin to Start Menu. Then, right-click on Premiere Pro in the Start Menu and do Properties --> Compatibility --> Run this program as administrator. Finally, to simplify even more, after doing the previous step, right-click on PPro and do Pin to Taskbar.
I having the same problem also.
Run as administrator are not working on my file.
Any other solutions?