I was able to view and download a person's full sized, high resolution profile picture on Instagram until even a few days ago. I usually remove the 's150x150' from the URL and it worked fine for me. But now when I try the same thing I get a error saying 'Invalid URL signature'. I don't know what's happened. Can someone find me a solution for this problem? Or an alternate method maybe?
replace "150x150" with 720x720 and remove /vp/ from the link.it should work.