Stepper Motor + Wemos D1 don't work, but works with Uno

I want to connect a Stepper motor to my arduino. I have downloaded a libary (CheapStepper.h)
When I try the example in the libary it works perfectly on my Uno, but when I connect my Wemos D1 I just get this strange message on the serial:
ets Jan 8 2013,rst cause:2, boot mode:(3,6)

load 0x4010f000, len 1384, room 16
tail 8
chksum 0x2d
csum 0x2d
v09f0c112
~ld

I have tried with 2 different Wemos, and also stepper codes that do not require the libary (http://www.instructables.com/id/BYJ48-Stepper-Motor/) and I can not get it to work.

Any one have any idea how I can resolve this?

#include <CheapStepper.h>

CheapStepper stepper;
// here we declare our stepper using default pins:
// arduino pin <--> pins on ULN2003 board:
// 8 <--> IN1
// 9 <--> IN2
// 10 <--> IN3
// 11 <--> IN4

// let's create a boolean variable to save the direction of our rotation

boolean moveClockwise = true;

void setup() {

// let's just set up a serial connection and test print to the console

Serial.begin(9600);
Serial.println("Ready to start moving!");
}

void loop() {

// let's move a full rotation (4096 mini-steps)
// we'll go step-by-step using the step() function

for (int s=0; s<4096; s++){
// this will loop 4096 times
// 4096 steps = full rotation using default values
/* Note:

// let's move one "step" (of the 4096 per full rotation)

stepper.step(moveClockwise);
/* the direction is based on moveClockwise boolean:

  • true for clockwise, false for counter-clockwise
  • -- you could also say stepper.stepCW(); or stepper.stepCCW();
    */

// now let's get the current step position of motor

int nStep = stepper.getStep();

// and if it's divisible by 64...

if (nStep%64==0){

// let's print the position to the console

Serial.print("current step position: "); Serial.print(nStep);
Serial.println();

}
}

// now we've moved 4096 steps

// let's wait one second

delay(1000);

// and switch directions before starting loop() again

moveClockwise = !moveClockwise;
}