Rstudio not displaying code

Hello, when I open an R code (.R, .Rmd) with Rstudio, the code is displayed on screen. The code is here (file size are non zero) and appears when i try to open it with the notepad. I tried reinstalling R / Rstudio (3.6.1 and 1.2.5019). Any way to check if Rstudio handle R files correctly ?

What happens when you try to open a file from Rstudio's using the menu bar File then Open File?

Are you trying to get Rstudio to be the default application when you double click a file?

Hi,
If you record a short video, gif, or screenshots, it would let the engineers know what has happened. From you description, it is hard to imagine what happened in my opinion.