The Website showing unable to connect

From last 2 days the website hassan-brothers.ae continuously showing "Oops! you can't see pages on this website." It's the e-commerce website and I'm the developer of it. I had to add more products for my client but unfortunately this problem occurs. I contacted to the hosting provider they said "I think some kind of sql query issue but your developer can help out better and early" after working on SQL it's working on other's end but I unable to access.

Kindly resolve my issue thank you.

[Edited by Moderator]