Stubborn new error: MD5 of file does not match data in flash!

My ESP Now system had collapsed, so I’m rebuilding it from scratch. I have a new sender and a new receiver. They’re working right now.
But when I tried to upload the same program for a Board 2, the program goes all kerplooey. I get serial gibberish.

So I wrote a new program to digitalRead analog sensors. I’ll add the ESP Now stuff when it’s working. But now it won’t let me upload anything. Other programs are also affected.
Here’s the whole thing:

#include <Arduino.h>

void setup()

  pinMode(0, INPUT);
  pinMode(5, INPUT);
  pinMode(6, INPUT);

void loop()
  Serial.print("LPG: ");
  Serial.println(" PPM");
  Serial.print("Smoke: ");
  Serial.println(" PPM");
  Serial.print("CO: ");
  Serial.println(" PPM");


So far, it handles two sensors, but it goes kerplooey at five. I’m trying to add them one at a time, but now it won’t upload due to this error:

Configuring flash size…
Flash will be erased from 0x00001000 to 0x00005fff…
Flash will be erased from 0x00008000 to 0x00008fff…
Flash will be erased from 0x0000e000 to 0x0000ffff…
Flash will be erased from 0x00010000 to 0x0004afff…
Compressed 17088 bytes to 11848…
Writing at 0x00001000… (100 %)
Wrote 17088 bytes (11848 compressed) at 0x00001000 in 0.3 seconds (effective 410.2 kbit/s)…
File md5: f5ff9b657c6048ed5c6ad1143d369a63
Flash md5: ac65ea7ae698c0df3f8f7931bdf77d8c
MD5 of 0xFF is ec6d40accaa061f64845241573f23ff8

A fatal error occurred: MD5 of file does not match data in flash!
*** [upload] Error 2
=================== [FAILED] Took 28.11 seconds ===================
The terminal process “C:\Users\joema.platformio\penv\Scripts\platformio.exe ‘run’, ‘–target’, ‘upload’” terminated with exit code: 1.