Everyone's had that problem. A dog, cat or person steps on your dart, and then that dart won't work anymore. Here's a fix.
Step 1: How to Fix
After stepping on a dart, it should look like pic 1. Then, pic 2 is putting it in a jolt(triad works too). About 3-5 mins later, take it out and test it.(pic 3)
Alternatively, take the dart and shove a yellow knex rod in it. The jolt/triad method works better though.