Crash

I got the forerunner 45s in may, and it's been working great.

But earlier today, after a 10km run, it glitched while saving and showed the triangle on the screen, as well as the gear thing? A few seconds later, it went back to the save menu, so I selected save and all seemed well.

When I synced with the Garmin Connect app, it showed my run perfectly fine, but the steps from the activity were not counted in the daily step count, nor were the active calories, or the intensity minutes, or the heart rate data. Usually, for all of my past activities, they have all been counted. Thankfully the run has been saved and the kilometer count has been updated, but I'm still a bit cheesed about the missing data. 

Is there any reasoning for the crash? Any way to prevent it from happening in the future?