The path the complete path to the file, including all the folders on the way to the file, for example "C:\Users\<your-windows-user-name>\Documents\Warcraft III\Maps\MyCustomAIProject\(4)HillsbradCreek.w3x" is 101 characters long path and should be ok. But if you have several "8ed916737dc5d566db70723b4962f0c0c2bb90a9" paths, each 40 characters long, it is possible to reach the limit.
What is saying "the path is too long"? The editor? Warcraft 3? Windows? Other OS?