If, for example, the link is to SFS, you can get all the way back to the account for the creator, find a list of their files for upload, and locate what you want that way.
You can work backward through the URL deleting elements until the thing works, and then proceed to search that site for what you want.
Sometimes a URL is not linked correctly because of an error when it was made, such as including a bracket or not getting the whole thing copied. If I type in this URL I can follow it normally, and I can also experiment with it. When I do that, I can see the URL linked down in the lower left hand corner of my screen. When you move the cursor to the link, check the obscure corners of your screen. If your browser and tumblr can't agree, you can probably do a workaround. Links to custom content on tumblr will lead you to a hosting site, such as MTS, SFS, box, etc.
Before we can tell you that we have to know what browser you're using.
