Why can't I get into Miraak's temple?

Solution 1:

You only need to place the four books you have found up to this point. You should then be able to activate the book on the fifth pedestal in the middle of the structure, and warp to Chapter VI. Provided, of course, that you put the books on the right pedestals:

Boneless Limbs is placed on the 'tentacle' symbol.
Delving Pincers is placed on the 'pincer' symbol.
Prying Orbs is placed on the 'eye' symbol.
Gnashing Blades is placed on the 'fangs' symbol.

For PC users, if the pedestal still won't activate, you can use the console command coc DLC2Book01DungeonEnd01. This will send you to the Chapter VI area immediately, and trigger that part of the quest.

For console users, I think the only fix will be to load an old save.

^Source