I was having an issue with Vungle, but not anymore with their latest plugin version.
One thing to note is that my project is an Enterprise project, which means I use Xcode to compile locally. I saw that Vungle had updated their plugin, and after linking in their new plugin version the issues were gone.
BTW.
I’m surprised that you say your app was working and then all-of-sudden it stopped working. To me that sounds like maybe you’re getting the latest Vungle plugin linked in although you’re using the public version (and that the plugin requires a later daily build).
I was under the impression that plugins were linked based on the build that was used. Maybe I’m wrong. However if you *are* getting a plugin that requires a later Corona build, there might be some bug with CoronaLabs “plugin chooser” which is giving you a version of a plugin that you shouldn’t get. Just a thought.