LuaRuntimeException - plugin_OneSignal.lua:78: json.decode called with nil string

I just updated the OneSignal plugin that I have in a Corona Native project and I noticed that every time the app receives a push notification, the following error appears in the console:

12-08 19:38:39.319 8637-8655/com.mycompany.app W/System.err: com.naef.jnlua.LuaRuntimeException: /Users/Kasten/Documents/OneSignal/GameThrive/SDK/Corona/SDK/android/../shared/plugin\_OneSignal.lua:78: json.decode called with nil string at com.naef.jnlua.LuaState.lua\_pcall(Native Method) at com.naef.jnlua.LuaState.call(Unknown Source:4) at OneSignal.LuaLoader$InitFunction$CoronaNotificationOpenedHandler$1$1.executeUsing(LuaLoader.java:159) at com.ansca.corona.CoronaRuntimeTaskDispatcher$TaskEvent.Send(CoronaRuntimeTaskDispatcher.java:170) at com.ansca.corona.events.EventManager.sendEvents(EventManager.java:91) 12-08 19:38:39.320 8637-8655/com.mycompany.app W/System.err: at com.ansca.corona.Controller.updateRuntimeState(Controller.java:318) at com.ansca.corona.graphics.opengl.CoronaGLSurfaceView$CoronaRenderer.onDrawFrame(CoronaGLSurfaceView.java:425) at com.ansca.corona.graphics.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1625) at com.ansca.corona.graphics.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1380)

UPDATE: I found out that the error above only happens if you send a push without any additional data.