Tween not working

[olleyoop]

Hello,

I'm trying to get the Tween lib running on my Uno.
But even when I try to get the simple usage example running I run into the following problems:

1. With the latest version 0.3.9 as well as 0.3.8 I get the following error when I verify the code:
   Compilation error: could not convert 'nullptr' from 'std::nullptr_t' to 'const TransitionCallback& {aka const arx::stdx::function<void()>&}'
2. With the version 0.3.7 there is no more error but after uploading it to the board I don't get any messages in the Serial Monitor.
   When I Modify the example to this:

#include <Tween.h>

Tween::Timeline timeline;
float target = 0.f;

void setup() {
  Serial.begin(115200);
  Serial.println("JO");
    timeline.add(target) // target tweens
        .init(0)         // init target value (optional)
        .offset(1000)    // delay start 1000[ms] (optional)
        .then(10, 5000)  // to 10 in 5000[ms]
        .then(5, 5000)   // then to 5 in 5000[ms]
        .hold(1000)      // then stops 1000[ms]
        .then(0, 5000);  // then to 0 in 5000[ms]

    timeline.start();
}

void loop() {
}

I get the following message:

15:7:24.536 -> ��JO�

Anyone with a clue on what's going on here?