Ok I see it now. Don't worry give yourself a bit of time.
Ok I am a little unaware of this extra, could you possible go into extras and show us the list, including this 'services management' please?
Also, please in the manager go to the error log and see if any errors are popping up at the time that you try to open the services page on the site.
Let's get a bit more info and then hopefully we can find a way forward.
Now I just want to note that, I see this site looks live, so I wonder if we might first focus on replacing the services section with something that at least will work. This would require some time and effort as well, so I am not sure whether to attack the root problem or first make a fix just so users don't see the blank page.
My thinking would be to replace (for now) the services options with one page, perhaps similar to your 'about' page. Possibly you could assemble the list of services in text, that way the users wouldn't even notice there is any problem, it won't be as nice as the menu but it would still look ok. We could use the about template to give it the same style.
Again I am not sure about the best way forward, but its an option you can consider. But, the text would end up looking something like this, its html so that the style of the content can be made nice (using css). If we looked at your 'about' page code we could make the same style.
<h1>Our Services</h1>
<p>We have many services to choose from.</p>
<h3>Coloring</h3>
<p>We can color your hair perfectly</p>
<h3>Cutting</h3>
<p>Our professionals are expert at all hairstyles.</p>
And so on, you probably should just copy and paste the content on services you have now, and a little arranging and it would be ok.
This is assuming we can't find a quick fix though. Still, it could take the pressure off a bit.