Classification msi images

I was trying to perform supervised classifications

Opened satellite image
Created vector file
Raster>supervised classification>random forest classifier>

Opened product

But in the next tab even though I created vector file in the main tab it’s not showing why?

The message in red tells you what is wrong. If you drag the window a bit you can read the whole message.

You need to resample the S2 data to a common resolution first. Afterwards it should work.