S3 - Major
My issue is this: the musescore program installed on my computer keeps crashing, and as a result, a large portion of my work would be lost. It is incredibly frustrating, and it is making me consider other sheet music making programs other than MuseScore, which seems to be unreliable. It pains me to say such statements, but the frequency of this scathing issue is completely ridiculous.
You attached an autosave version of your score, do you have the real score too? What are the steps leading to the crash?
The score looks corrupted beyond repair, opening the msvz with 7Zip shows the mscx inside to have a size of 236269 bytes, but a compressed size of 0.