My VSTAR will not recognize text files sitting in a directory with the “New Star from File…” option

 I have been running VSTAR a lot on my old MacBook Pro, where the usual mode is to take my own light curves into a text file (just a listing of HJD and mag for many lines) that I usually name “ft.dat”.  When I got a new MacBook Pro (running MacOS Big Sur version 11.4), roughly two years ago, my old system was ported to the new laptop, but VSTAR did not work at all.  Recently, I tried downloading the most recent version, but could never get it working.  The thought was that the new improved processor on my latest laptop (Apple M1 chip) was incompatible with VSTAR.  So I kept up my old laptop, mainly just to run VSTAR.  After a year, I tried downloading a new version of VSTAR, thinking that such a problem would inevitably have been fixed.  I could get VSTAR to open and run OK.  Or at least, I could get Fourier transforms of data files imported with the “New Star from AAVSO database…” option (under “File”).  OK, so it is basically working.  But when I tried to have it “New Star from File…” option, the “Open” popup screen would always be blank, with no options to upload any files.  I would create new files, like “ft.dat”, or “ft” or “ft.txt”, in a variety of ways, but they would never be shown as options on the Open box.  In the “Open” box, the pull down “File Format” menu has only the option “‘csv’, ‘dat’, ’tsv’, ’txt’”.  My wife (who knows a lot more about these sort of things than I) played around with it a lot (like downloading VSTAR yet again), but could never make a change.  So at this point, I cannot have VSTAR read datafiles for my target stars, so it is broken.  (My current version of VSTAR is 2.22.0.)  What can you recommend for trying to fix this?