CheckForm doesn't like special characters or blank spaces in the path or folder names. Remove the "&" from the entity-year folder name; use something like John_Martha instead. Then Checkform will find the lsr file it needs.Additional information:
It is good practice to avoid special characters, blank spaces, and long folder and file names. Many programs don't care, but CheckForm and many other programs won't be able to find data if the path is is too complicated.
Underscore "_" is a special character but is OK to use. So is a period "."
Navigator is often installed in the "Program Files" folder. The blank space in that folder name may prevent CheckForm from working. Using a mapped drive like you are doing ("F:") is an excellent solution.