I am getting 404 crawl error increasing day by day with specific url patterns. But in the source url, i can't able to find such thing of 404 error url. I checked with my developers also for the same. I have checked in my website source code thoroughly. But not able to find where this 404 error url forming?

Guys, can you please help on this.

Please see the attachment file with the details of 404 url and source url.