I just upgraded to Unity 5.1.1p3 and exported my app to IOS which when opening I get this warning:
Unexpected code bundle “Unity4XC.xcplugin”
The “Unity4XC.xcplugin” code bundle is not provided by Apple. Loading code not provided by Apple can have a negative effect on the safety and stability of XCode or related tools
???
To put it simply, Apple does not like third-party plugins and in recent Xcode versions, a warning dialog is shown. The solution is to agree to load the plugin.
@povilas - What happens if we’re running an automated build (using Jenkins, for example) where Xcode is running in batch mode? Does the plugin load and what if anything breaks in the Unity build process if the plugin doesn’t load?
I was having this issue, if I remember correctly the solution for me was to add the current UUID of your installed version of XCode into the Unity4XC.plugin plist (That process is described in more detail here).
And then make sure you have actually manually opened the project in XCode, on your build machine, so that it can present you with the warning dialog. After that, the issue was fixed for me (Unity 5.1.2p3, XCode 6.4)