Occasional error when importing XML file into Finale

I sometimes get an error message when I import an xml file created with MuseScore into Finale. The error message says "The content of element type direction-type is incomplete, it must match..." What does this error mean? I contacted MakeMusic, who told me this is generally a syntax error in the xml file itself, and does not have anything to do with Finale's file import. The only real difference between the original MuseScore file and the Finale file resulting from the xml import - and I'm not sure that has anything to do with the error - is that instead of just one bracket on each system, there are two (adding a piano bracket). Since everything looks fine except the extra bracket, it's not a major problem, but I'm curious to know what this error means and why it only occurs occasionally, although I repeat the exact same procedure every time I export from MS. The issue first occured when using MuseScore 3.3, but appeared again with the same file (though not the one attached, but same error message) after upgrading to 3.6.2. I also tried exporting the MS file both as *.mxl and *.musicxml, to no luck.
I attach the original MS file, a screen capture of the resulting Finale file, a printscreen of the error message and the xml file.