unitizer version 1.4.12 does not install

To avoid autoflaging of your posts, post console output as formatted code, here is how to do it

About your issue, I'm afraid you are not providing any relevant information, please post the actual error message you get (as formatted code), also, why do you have both versions installed? Make sure to uninstall any previous version from your other library paths (you can get them by running .libPaths()).