Problem uploading images in slideshow in portfolio format

I’m using wordpress 3.8 and the gridlocked theme which has the portfolio page template. I can create the individual project portfolio such that it shows up as an icon on the portfolio page but I am unable to upload images in a slideshow to the portfolio itself and when I click on the project icon it goes to an Error 404 – Not Found page.

I don’t know whether this is relevant but when I try to upload the images, after clicking browse for the image and clicking on the image that I want, there’s no “insert into post” button although that’s what the instructions say farther up the page. There’s only an “Insert” button, although this doesn’t seem to do anything.

Any help would be appreciated.

to see the problem:
katherineortmeyer.com