Why does my galaxy s5 keeps restarting every time I try to connect to the WiFi?

Recently my phone has been restarting by itself. And now it's gotten worse. Every time I try to connect to the WiFi it automatically restarts. Can someone help?

Welcome to Android Central! Do the restarts only happen when you connect to wi-fi? Is it only one particular wi-fi network?

Try wiping the system cache partition: http://support.t-mobile.com/docs/DOC-10404

Well before this it would just randomly restart and I noticed that it would happen more often when I had weak signal. But now it restarts when I try to access the WiFi.

I also tried what you told me and it didn't work it still keeps restarting.

Try booting into Safe Mode, which prevents all 3rd party apps from starting up. If the problem goes away, then something you installed is probably causing the instability. Instructions for Safe Mode are in the same link I posted previously.

I had a similar problem. I used Samsung's PC software Kies to update the OS and it seems to have fixed it.