MODx-based website: Getting 500 Server Error

MODx-based website: Getting 500 Server Error

I'm not a MODx developer, but trying to work on a website that is based on
MODx.
I just tried adding a resource under another resource that also involved
uploading a file. Then I went ahead and deleted the resource. Now, when I
refresh the page, all I get is just a 500 Server error.
Any idea what might be causing this? I've already deleted the cache as well.