java.lang.NullPointerException

[redpandatronicsuk]

Just got this crash report through Firebase Crash Reporting. Looks like it is caused by RevMob.
Stacktrace:

Exception java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.WindowManager android.app.Activity.getWindowManager()' on a null object reference
com.rctrevmob.RevMobModule.loadBanner (RevMobModule.java:258)
java.lang.reflect.Method.invoke (Method.java)
com.facebook.react.bridge.JavaMethodWrapper.invoke (JavaMethodWrapper.java:363)
com.facebook.react.bridge.JavaModuleWrapper.invoke (JavaModuleWrapper.java:166)
com.facebook.react.bridge.queue.NativeRunnable.run (NativeRunnable.java)
android.os.Handler.handleCallback (Handler.java:751)
android.os.Handler.dispatchMessage (Handler.java:95)
com.facebook.react.bridge.queue.MessageQueueThreadHandler.dispatchMessage (MessageQueueThreadHandler.java:31)
android.os.Looper.loop (Looper.java:154)
com.facebook.react.bridge.queue.MessageQueueThreadImpl$3.run (MessageQueueThreadImpl.java:194)
java.lang.Thread.run (Thread.java:761)

Info about the device it crashed on:
Manufacturer: Wileyfox
Model: Swift 2 X
Board: Marmite
Android API: 25
Android OS: 7.1.2
Brand: Wileyfox
RAM: 2.8GB
Orientation: Portrait