Rich edit textbox

Question

Hello,

I have created an UWP App with richedit text box (VB)

People can write,

navigate between several reports, forms, etc. lists, etc.

then, can save to .rtf using storage file.

When I open in word can read all characters: Ñ ó,á,éíú. perfect.

But in Nopepad see the ANSI HEADER.

When OPEN in the app. can´t read the special character ( Ñ á, " " -) only that.
The richedittexbox respect the parragraphs, etc .. THE DATES ARE CORRECT.
CAN REPLACE THE PAR TAB.

Use storage file to open

If I change data in wordpad. The file cAn´t be OPENED in the App.
Yes I can modify IT in the app. perfectly, but without ÑÑ

So can you suggest the code??

THANK YOU.