At least you have found the problem, well done.

Keep folder & file names short, it makes them easier to identify & remember. Also keep in mind that the file name path could include the sub folder name, the name of the main folder, what directory it is in, & the name of the program that the original file came from & this path is not known to you when you are naming a file, unless you have it in mind. So you can see that this could easily exceed the file naming limit.

This MS website might help you.

Naming Files, Paths, and Namespaces (Windows)