Resizing cursor to screen size

I want to have the cursor scale with the screen size.

My cursor was imported from a PNG to a sprite. I added a function to scale with screen size and put that function in Update().

This is the line of code that is causing issue:

 currentCursor.Resize ( ( int ) ( cursorScreenRatioWidth * Screen.width ), ( int ) ( cursorScreenRatioHeight * Screen.height ) );

The error:

 "Can't resize to a compressed texture format."