It seems that multimc has difficulty extracting filenames with special characters in them. Specifically it seems to choke with the § section symbol.

24.162 W Failed to extract file "resourcepacks/Better-Leaves-6.0-1.13+\u00156.zip" to "resourcepacks/Better-Leaves-6.0-1.13+\u00156.zip"

this is reported a couple times on their discord server and also in an open issue on github MultiMC/Launcher#4182

Fixed.