Factorio v2.0.33 (currently Experimental) has "Removed unused spritesheets from the game data folder.", which breaks this mod with error: "Failed to lod mods: File base/graphics/entity/cloud/cloud-45-frames.png not found". This was confirmed to be intentional and not related to the current Clouds implementation in https://forums.factorio.com/viewtopic.php?t=126409.
Copying the named File from a v2.0.32 Installation resolves it temporarily; this Mod will need to be updated to include this File (or a derivative, as permitted by the Factorio Terms of Service); or update to use a different asset entirely.
Thank you for the hard work keeping this Mod running. Good Luck!