what happened?

After a few years the door hinges wear out.Then the weight of the door is on the striker. Over time the weight is too much stress on the metal and it cracks.This is a poor attempt to fix it.You need to cut out the metal cut and replace it,adding a reinforcement plate behind the new metal is a good idea..They also sell a kit for this repair.The door hinges also need rebuilt at this time to avoid the metal cracking again.

Jim