My website does not load the enlarged image

[haykgrigory]

I have a little problem with the additional images, that I am having trouble fixing.

I upload the first image through the admin into the main directory and name it testprod1.jpg (750x750 px) and it shows up correctly (screenshot #1)

If I click on that image it enlarges the image and properly using the lightbox (screenshot #2)

Then I create the second image, name it tesprod1_2.jpg (750x750 px) and upload it to the same directory as the original is. It also shows up in the product page correctly (Screenshot #3)

This is where the problems start
When I click on the additional image it starts loading the image, but never actually loads it (screenshot #4)

1 thing that I have noticed that the first image still loads and on the right bottom corner it says image 1 of 2 (screenshot #5)
but when i click next it does the same thing in screenshot #4

Does anyone have any ideas on what is causing this problem and how can it be fixed. Thanks