full text of the error:

{{Failed to download file.}}
{{Name: be_by.json}}
{{URL: https://resources.download.minecraft.net/17/173db3c64a470179b91df1562bcdbfb750d54328}}
{{Filename on disk: 173db3c64a470179b91df1562bcdbfb750d54328}}
{{Path: C:\Users\David\AppData\Roaming\.minecraft\assets\objects\17\173db3c64a470179b91df1562bcdbfb750d54328}}
{{Exists: Nonexistent}}

It seems to just erase the file if I download it and then say it does not have it.