"Cannot create a file when that file already exists" on game startup

You may need to reinstall the locally installed files that Minecraft puts into place.
To do so, press your Windows+R keys, type in %AppData% at the dialog, and press Enter. In the window that appears, open the .minecraft directory, and delete everything except for the saves directory that you see therein. Then, try running Minecraft again. If this doesn't fix your issue, please comment on this ticket again.

now it says

ERROR 😞

Unable to create directory. fire_crackle4.ogg
Name: fire_crackle4.ogg
URL: http://resources.download.minecraft.net/73/739dc564cf6d0ff909542293cd5754d4aa52bf2c
Error details: Cannot create a file when that file already exists
Filename on disk: d037-c548-cafc-65f2
Path: C:\Users\twigs909\AppData\Local\Temp\d037-c548-cafc-65f2
Exists: file

or do you think I might have undeleted minecraft files that cause the error?

This is MCL-5546