Strange error (not enought memory)

When I click the keyboard’s button, nothing interesting appears:

// --------------------------------------------- обработка нажатия клавиши на клавиатуре ---------------------------------------
void cb_keyboard(lv_event_t * e){
    lv_event_code_t code = lv_event_get_code(e);
    if(code == LV_EVENT_CLICKED){                                                   // надо попробовать LV_EVENT_VALUE_CHANGED
        uint16_t bt = lv_keyboard_get_selected_btn(keyb);
        //Serial.println(bt);
        if (bt == 12){
            //Serial.println("backspace");
            lv_textarea_del_char(message_text_input);
        }
        else if (bt == 24){
            //Serial.println("Enter");
            lv_textarea_add_char(message_text_input, '\r');                         // если не переносит - заменить на \n
        }
        else if (bt == 25){
            //Serial.println("Shift");
            if (lv_keyboard_get_mode(keyb) == LV_KEYBOARD_MODE_USER_1){
                lv_keyboard_set_map(keyb, LV_KEYBOARD_MODE_USER_2, kb_ru_big, matrix_ru_big);
                lv_keyboard_set_mode(keyb, LV_KEYBOARD_MODE_USER_2);
            } else if (lv_keyboard_get_mode(keyb) == LV_KEYBOARD_MODE_USER_2){
                lv_keyboard_set_map(keyb, LV_KEYBOARD_MODE_USER_1, kb_ru_small, matrix_ru_small);
                lv_keyboard_set_mode(keyb, LV_KEYBOARD_MODE_USER_1);              
            }

            
        }
        else if (bt == 38){
            //Serial.println("rus/eng");

        }         
        else if (bt == 46){
            //Serial.println("123");
            lv_keyboard_set_mode(keyb, LV_KEYBOARD_MODE_SPECIAL);                   //LV_KEYBOARD_MODE_NUMBER
        } 
        
        
        else{
            const char * txt = lv_keyboard_get_btn_text(keyb, bt);
            lv_textarea_add_text(message_text_input, txt);
            
        }
    }
}

but application hangs…