The issue for me was caused by updating Unity IAP and not having a high enough API installed:
Android SDK API Level 24 (7.0)" (or higher) must now be installed. To upgrade, either perform the one-time step of setting the project’s “Android Player Settings > Other Settings > Minimum API Level” to 24, building an APK, then resetting to the project’s previous value. Or, run the android Android SDK Manager tool manually and install “Android 7.0 (API 24)”.
Jadara
22
for me i just deleted my plugins folder… it only deletes the stuff i dont need
