I cannot even try to upload/download anything...

I've got 2 test sites/zencart installs. First one I upgraded to 153, clicked on tools>Easy Poplulate 4 and got basically a white page with only that error message on the page.

So, I thought with the other test zencart, I'll click on tools>EP4 and click on the uninstall first, then go an upgrade to 153, then go back to tools>EP4 and click on install, but instead got the same white page with the error message.