When i try to delete my “Product” i receive this error “You have no authorisation for this page”, only after 5-6 attempts i have delete (i have try also with chromium and same problem), when i have upload a file (i have upload only image) i receive forbidden request error, but only after many attempts, i have upload some images, (my english is not good)
a different browser, or
within the same browser:
* a private window, or
* a new (Firefox/Chrome/etc) profile, or
* clean the browser cache.