Hi All,
I have faced a problem in my website that I couldn't log in to the admin panel after almost 4 days of successful installation. It was working fine and in one day I tried to open the admin panel through many computers and it didn't work.

the sign in page was showing normally, but after I put the email and password it will show just a white page or HTTP ERROR 500.

today I tried to access Arastta admin panel the demo one and it was showing to me the same problem.

this is the admin panel link
http://demo.arastta.org/admin/index.php?route=common/dashboard&token=ff5f3fe76181ada7b3673663459d4303

and I have attached a picture of the issue as well.

I actually had to delete everything

I did setup the Arastta on paid hosting.

can anyone advise me on this?