Lets just say I had a similar issue with a file in the UE4. Like you I couldn’t find the settings somewhere in the editor of what is was asking for so I could point it somewhere else.
So I broke out MVSE 2014 and started opening up my projects code files and looking through them for something that had that exact same object or directory or whatever called for. Once I found it and looked at the path it was calling all I did was just change the path in the code and it solved my problem.
So pull out notepad ++ or something and look over the code for where that path is stated and change it.