IndieDoroid Because on the main project, whenever I re-import the libraries I always get warning pop ups saying some spine example files being version 4.0 and weren't imported correctly. (because I updated all the spine files and runtimes to version 4.1)
Then I assume that you then did not cleanly remove the 4.0 runtime before installing the 4.1 runtime (as described here), and thus have some leftover 4.0 files remaining which trigger the warning. Unless you have modifed the spine-unity runtime files, I would recommend removing your potentially "mixed" 4.0 / 4.1 runtime again and installing the latest version of the 4.1 runtime cleanly. As always, backup your project first, just in case anything goes wrong or if you forgot about some modifications you did to the runtime.