(Solved) Strange com.naef.jnlua.LuaRuntimeException error

I started to see on my logCat the following error.

It happens after the transactionCallBack of store.restore() has been executed (using both Google IAP v2 or v3). The error appears on the logCat but don’t freeze or crash the app.

What that might be?

05-14 18:34:48.699: W/System.err(24312): com.naef.jnlua.LuaRuntimeException: ?:0: attempt to index field '?' (a nil value) 05-14 18:34:48.703: W/System.err(24312): at com.naef.jnlua.LuaState.lua\_pcall(Native Method) 05-14 18:34:48.703: W/System.err(24312): at com.naef.jnlua.LuaState.call(Unknown Source) 05-14 18:34:48.703: W/System.err(24312): at com.ansca.corona.CoronaLua.dispatchEvent(CoronaLua.java:100) 05-14 18:34:48.703: W/System.err(24312): at network.NetworkRequest$LuaCallback$1.executeUsing(NetworkRequest.java:603) 05-14 18:34:48.703: W/System.err(24312): at com.ansca.corona.CoronaRuntimeTaskDispatcher$TaskEvent.Send(CoronaRuntimeTaskDispatcher.java:148) 05-14 18:34:48.703: W/System.err(24312): at com.ansca.corona.events.EventManager.sendEvents(EventManager.java:87) 05-14 18:34:48.703: W/System.err(24312): at com.ansca.corona.Controller.updateRuntimeState(Controller.java:281) 05-14 18:34:48.703: W/System.err(24312): at com.ansca.corona.graphics.opengl.CoronaGLSurfaceView$CoronaRenderer.onDrawFrame(CoronaGLSurfaceView.java:417) 05-14 18:34:48.703: W/System.err(24312): at com.ansca.corona.graphics.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1622) 05-14 18:34:48.703: W/System.err(24312): at com.ansca.corona.graphics.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1377)

UPDATE: Solved. The problem was inside my code (in a function that was called during the store.restore())