Sorry, you are not allowed to access this page

Hi,

When i click on “About Tyche” i see the warning (rounded at photo)

And when i click on “TGMPA Plugin”, it says “Sorry, you are not allowed to access this page.”

My main problem is Slider disappears when i try to upload a new photo. I tried many times, checked plugins, did everything…

Your demo content file links are not working so i found them from another source on the web…

Can you pls help me?