http://feedback.arma3.com/view.php?id=20501

First of all, make sure it's on your end. Does the game crash when playing the campaign or other scenarios?

Altis/Stratis life and Wasteland are notoriously unstable and laggy because they deal with very large amounts of equipment being randomly spawned around, and often have many people on them. Be sure to try validating the integrity of your Arma 3 cache in the game's steam properties.

Try uninstalling and reinstalling the game. When you uninstall, be sure to delete all files in your profile (documents) and root (Common/Arma3) to insure that all files are deleted. Then try reinstalling.

windows 8.1, multiplayer, same thing

happens to me too since last update, before it was ok now almost cant play 10 min in a row without crashing...

Has happened to me during single player campaign, and have tried uninstalling/reinstalling, and deleting files.

Hey, could you please attach the crashdumps again with mdmp files as well? You can use some file sharing device. It would help us a lot. Thanks again.

Here are all the crash files, including the mdmps, I believe there are 8 crashes in total over the course of 3 days, put into a zip file and uploaded to mediafire. Thanks for the response, Iceman!
http://www.mediafire.com/download/o455tmymi41xcu2/Arma_3_Crashes.zip

Hello,
these crashes are unfortunately known issue for 1.28 Stable version. I am closing this ticket as duplicate, please keep track of the linked original one.