SocketReader read() returning null

[prianck]

I had experienced a crash in the app pointing to the library's ReceiveThread's run() function. here
I was wondering what could probably cause a NPE at reader.read()

[prianck]

Stacktrace
Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'byte[] j.a.a.c.b.a()' on a null object reference at me.aflak.bluetooth.Bluetooth$ReceiveThread.run(Bluetooth.java:556)

[Tho391]

Same issue:
E/AndroidRuntime: FATAL EXCEPTION: Thread-15 Process: com.bosch.aquaeasy.dev, PID: 30888 java.lang.NullPointerException: Attempt to invoke virtual method 'byte[] j.a.a.c.b.a()' on a null object reference at j.a.a.a$i.run(SourceFile:556)