Hello, thank you very much for answering Réna.

It's weird, maybe my flash memory is corrupted.

I am using an Arduino MKRZERO and I am connecting the pins of MISO, SCK, MOSI and 5 for the CS, in addition to the pins of VCC and GND.

But it just won't let me write any data. 

Hi everyone, I am currently using the "TinyCircuits TinyShield Flash Memory: Sketch Example" for arduino, but when compiling and loading it to the board it does not allow me to write to the flash memory.

This is the result I get on the serial monitor:

---------------------------------------------------------------
Initializing Flash Memory...

Using writeByte...
Write failed!
Using readByte...
The byte on page 2468 at position 78 is: 0
---------------------------------------------------------------

I have tried using the SPIFlash.h and SPIMemory.h libraries, but I keep getting the same error.

Does anyone have an idea what could be happening?

I would greatly appreciate your help!!

Greetings.