Game crashing

[ereedks]

In the last month or so the game freezes then crashes. Sometimes it happens within ten minutes or so of starting a game, other times an hour or more after playing. I haven't played the default maps very much so I don't know if it happens on them as well, but it happens on several modded maps. The log shows "Error: Render device Error: Unknown." I've seen others with the same error message when I searched the web for the error message but most were using FS17 instead of FS21. I saw one response was to change Direct X 12 to Direct X 11 but that didn't fix it. My system is using an Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz 3.60 GHz processor and has 16 GB RAM. Any ideas?

[hallfastrac]

A Render device Error is your graphics card which renders the images you see in your game Update your driver if needed, test your card with heaven benchmark for over heating and rendering frame loss