Musescore's Path Name Length Limit Is Less Than Window's Limit

I saved a score to a longish file name - maybe 40 characters; then when I tried to open the new file, Musescore reported "Can't read file ... " unknown type. See the attached screen shot "Musescore File Name Length Issue - Path Length.PNG".

I then did a File / Open, and in the open dialog, tried to shorten the name (with the file extension not visible). Musescore responded that changing the file extension night render the file unusable.

This was all down a deeply nested path with long folder and file names, so I think Musescore is truncating the total path name, losing part of the file extension, and then not recognizing the file. Here's the full path name:

E:_DataGtd\Songbook\Scores (Musescore)\Dunn, Greg Compositions\Musical Diary_Actively in Development\Songs with Lyrics\M04_Getting Close\2018-08-23_Till Me You Choose\2019-03-20_Piano Rendering of Till Me You Choose

Screen shots attached.