What is a buffer overflow?

The 'buffer stack' is the list of commands your system is performing; like a laundry list.

Those are done in order, top down.

An 'overflow' or 'overrun' can occur because just too many things are going on, but, one widely used method to inject 'bad' commands (in order to install malware) is to flood the buffer, which then 'kick out' the top legitimate commands, and replaces the lower commands with the "payload", which then moves up the list to be executed.

If you get this 'error' window while connected to the Internet, I'd disconnect and do malware scans to verify system cleanliness; then review what your static & dynamic securities are (firewall, anti-v, configurations, etc.) and see if you've let down your guard, or have been compromised somehow.

Again, it could be just internal software issue(s), but always play it safe.

Good luck.

This happens when a program takes in more data than it is designed to handle and doesn't react appropriately. This is caused by bad programming of said program. Either update whatever program is crashing or uninstall it. If your antivirus is catching it then the buffer overflow is most likely malicious.