Putting it all together, "1vanillaplusv2111821192zip" might be a ZIP file labeled as version 2.11.18.21.19.2 of the "Vanilla Plus" software. Maybe it's a software update or a configuration pack. Alternatively, it could be a mod or add-on for a game that's been modified, with the vanilla version plus some additions. Since the user might be referring to a specific software or game mod, I should consider that.