Windows Deployment of GUI Error: "Previously Accessable File <filename> is now inaccessable". Why?

I have completed a MATLAB GUI that does circuit synthesis of RF Filters. No external tools are being used. I am trying to generate a Windows Executable using the Deployment tool, but keep getting this error:

{Previously accessible file "C:\Users\gaukelk\Documents\MATLAB\Filter_Only_05.m" is now inaccessible. } MATLAB:fileHasDisappeared

Info about tool: 1. Uses temporary *.csv files to store temporary data, but that info is in the pwd and the isdeployed function is being used - though I don't really know how to use it in a GUI.

2. I have to run the executable in a "Sandbox" allocation of my hard drive due to security issues where I work.

Please advise.