When placing certain resourcepacks into the resourcepack folder, sometimes they don't show up in the resourcepacks screen and spam the log with [14:18:13] [Render thread/WARN]: [recursiveresources] Failed to determine source folder for pack: file/example.zip, unknown pack type: net.minecraft.class_8614, but they do without recursive resources installed, for example any resourcepack from https://vanillatweaks.net
Here is an example:
example.zip