is
Checks the specified ZIP-archive for validity. In order for a modpack ZIP-archive to be considered valid, it needs to contain the mods and config folders at minimum. If any of manifest.json, minecraftinstance.json or config.json are available, gather as much information from them as possible.
Return
false when no errors were encountered.
Author
Griefed
Parameters
pack
Instance of PackConfig with a server pack configuration.
config
Collection of encountered errors, if any, for convenient result-checks.