I changed the location of my saved manuscript and I have lost the ability to use the thesaurus. The files are still there, but something is missing.
Welcome to the Community 
Moving your manuscript to a different location should not affect your ability to access functions like the thesaurus.
Was the document originally saved in the Papyrus Author Documents folder? Did you move just the manuscript or other files/folders as well?
Can you confirm what you mean by this? The thesaurus should show the synonyms for each word in the context menu:
Are you unable to see these?
Or do you mean the bespoke dictionary files?:
You can see the additional dictionaries in the “Correction” tab of the Preferences dialogue:
Is this what you mean by “something is missing” - that you can see the dictionary listed in this dialogue, but it is not listed in the context menu when you right click with the mouse on a word?