"I don't think bytefence is installed anywhere on the pc.
Could there possibly be a different reason why this error occurs?"

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: f81f-37af-a206-3140
Path: C:\Users\twigs909\AppData\Local\Temp\f81f-37af-a206-3140
Exists: file