As you mentioned, for same code it works and then after sometime for same code it doesn't work. It was exactly similar issue in my case. As I earlier said, I figured out the piece of code which was reading a cookie and decrypting it on every request. That cookie we were setting when we navigate through our website. Now when there is an old cookie and code tries to read that cookie it fails.Clearing that cookie was making it work, but then after sometime or some other day we were facing this prob...

I faced exactly similar issue, where on my browser I was seeing this error message -:"Cannot serve request to /libs/granite/core/content/login.html in /libs/granite/core/components/login/login.jsp"Then after checking logs I saw there was a custom code which we have written, to use AEM Cryptosupport class unprotect method. Where we were passing some cookie value to be decrypt. This cookie value was cached in my local browsers and hence on any version of AEM or any browser only in my local instanc...