If you try to add an application to a menu that has more than 15 characters in its name, it will be “greyed out” in production. This is NOT the case while in development.
In my case, I had my menu set to not show menu labels that did not have applications assigned to them. This caused a nightmare in production, because unless you went into production you kept on thinking it was not uploading or there was a different issue since you could see it in development.
