error with Firefox Binary 'The browser appears to have exited'

[me at haseeb.co]

Have you tried specifying the location of Firefox binary explicitly ?

from selenium.webdriver.firefox.firefox_binary import FirefoxBinary
binary = FirefoxBinary('C:\Users\aplusk\Documents\FirefoxPortable\App\Firefox\\firefox.exe')
browser = webdriver.Firefox(firefox_binary=binary)