SPIFFS of ESP8266 problem

Hi

I have a HTML code that I want to upload that to my ESP module and see my web server in browser.

I can upload the image successfully and give the message Upload image Done

But I dont see anything except these messages in serial monitor:

ets Jan 8 2013,rst cause:4, boot mode:(3,6)

wdt reset
ets_main.c

and the code That I use in the IDE is:

to get som details about my code:
I connect to my home Wi-Fi and after that module gives me an IP address that when I print that in my browser the web server will shod.The first time I have try the web server By put my HTML in string and send it but after completing my web server I decide to use FS.

// Very basic Spiffs example, writing 10 strings to SPIFFS filesystem, and then read them back
// For SPIFFS doc see : https://github.com/esp8266/Arduino/blob/master/doc/filesystem.md
// Compiled in Arduino 1.6.7. Runs OK on Wemos D1 ESP8266 board.

#include "FS.h"
#include <ESP8266WiFi.h>
 
const char* ssid = "Amir";
const char* password = "911183012";
 
WiFiServer server(80);
 
void setup() {
 
  Serial.begin(115200);
  delay(10);
 
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
 
  WiFi.begin(ssid, password);
 
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
 
  server.begin();
  Serial.println("Server started");
 
  Serial.println(WiFi.localIP());

  bool ok = SPIFFS.begin();
  if (ok) {
    Serial.println("ok");
    bool exist = SPIFFS.exists("/tabs.html");

    if (exist) {
      Serial.println("The file exists!");

      File f = SPIFFS.open("/tabs.html", "r");
      if (!f) {
        Serial.println("Some thing went wrong trying to open the file...");
      }
      else {
        int s = f.size();
        Serial.printf("Size=%d\r\n", s);
String data = f.readString();
        Serial.println(data);

        f.close();
      }
    }
    else {
      Serial.println("No such file found.");
    }
  }
}



void loop() {
 
  WiFiClient client = server.available();
  if (!client) {
    return;
  }
 
  Serial.println("new client");
  while (!client.available()) {
    delay(1);
  }
 
  String req = client.readStringUntil('\r');
  Serial.println(req);
  client.flush();

  delay(1);
  Serial.println("Client disconnected");
}

How do you upload the image? With IDE menu option "ESP8266 Sketch data upload"? Are your data in project subfolder data? Did you set the correct flash size in Tools menu?