External interrupt Nucleo f072rb

I'm having unsolvable problems with my Nucleo f072rb.

I'm trying to use push-button as an external interrupt.

#include "mbed.h"
#include TextLCD.h
TextLCD lcd (PC_8, PB_8, PC_6, PC_5, PA_12, PA_11); //rs, e, d4-d7
Timer debounce;

InterruptIn tipkalo(PB_5);

void hwprekid(void);


void hwprekid()

{
    if(debounce.read_ms()>200)
    lcd.printf("Temp is:");
    debounce.reset();
}



int main()
{   
      debounce.start();
   
    tipkalo.rise(&hwprekid);       

    }
}

And the error I get is:

                                                           ++ MbedOS Error Info ++
   Error Status: 0x80010133 Code: 307 Module: 1
                                               Error Message: Mutex: 0x200010B8, Not allowed in ISR context
                           Location: 0x800927F
                                              Error Value: 0x200010B8
                                                                     Current Thread: main  Id: 0x200017F0 Entry: 0x8006CC1 StackSize: 0xC00 StackMem: 0x200003E8 SP: 0x20003EC8
                For more info, visit: https://mbed.com/s/error?error=0x80010133&tgt=NUCLEO_F072RB
                 -- MbedOS Error Info --

I'm really a newbie in MBED systems. Can anyone please help? Thanks in advance, Lukas