Some issues can be resolved by repairing common libraries after the upgrade. Doing a fully clean install of Windows 10 (or upgrade with loss of data - carefully back-up first please!) can resolve such issues. See tips about configuring the Steam browser here.
If the game crashes on start-up or refuses to connect to any multiplayer sessions, please try to disable these programs (or configure them by adding exceptions as needed). Some anti-virus programs or firewalls can prevent the start of the game or hamper it running smoothly.Savegames from previous versions may not be compatible with newer versions when loading (and vice versa)., Arma 3 F.A.Q. or BattlEye F.A.Q. for common troubleshooting, or this guide for Launcher troubleshooting. Visit the Bohemia Interactive support F.A.Q. This list is a sampling of the most obvious known issues within our team. Also see our Feedback Tracker for reported issues.