SharePoint 2010 ‘500 Internal Server Error’

From last many days customer stated facing intermittet issue of ‘500 internal server error’.  Organization have user from multiple geographical location e.g. USA/UK/JAPAN/INDIA

Strange : user from UK only faced ‘500 internal server error’ during specific GMT time duration i.e. 3:00 pm to 4:00 pm and at that same time user at USA was not facing any issue like this.

Final Solution: I started investigation from ULS log/eventviewr/Fiddler2 but no luck, after investigating for 2-3 days i found that one of entry in web.config did not have closing tag and that was really strange and it this internmittent behaviour because of configured H/W based load balancer and missing closing tag – that is why USA  based user was not facing ‘500 internal server error’ between 3:00 pm to 4:00 pm GMT and same time UK based user was facing that issue.

Note: ‘500 internal server error’ can have multiple number of reason and above one is one of them.

Cheers!!