I am trying to figure out how to develop Vuforia 5.5.9 using Unity. I made a test project which works with my laptop's webcam, but when I try to put it on a phone, which is running Android 5.1.1 Lollipop, I get a grey screen which says "Vuforia Initialization Error" and "Failed to Initialize Vuforia", and at the bottom there's a "Close" button. This seems like the same error people get when they run into Android M permission issues (https://developer.vuforia.com/forum/device-support/android-m-vuforia-initializing-failed), but I don't have Android M involved anywhere in my build. I am using the Android sdk version 22 (lollipop), have minSdkVersion="19" and targetSdkVersion="22" in my manifest, and, as mentioned before, am running 5.1.1 on the phone.
How can I get more information about what's going wrong? I'm new to Vuforia and Unity development so I don't know how to get more detailed information about the failure (or if that sort of information is even available). All I know is that it's giving me the "Failed to initialize Vuforia" error, and whenever I google that error I ONLY get results about the Android M permissions bug, which can't be affecting me.