Game crashes at alien island

[Harlequin]

Mostly everytime when I enter the island with the landing site and the big alien gun the game crashes. The screens goes white because the game hung up and I crash back to desktop. I had crashes like that a couple of times while I were playing so I got used to it somehow. I just try to save every now and then. But those crashes on said island really become annoying. Most of the time I get a crash, sometimes I can proceed with the story.
I tried several work-arounds already. Deleted files in the savegame-folder as the guide says. Doesn´t help at all. I get the same crash with the fils in the folder or without.
I hope someone out there can help me because it´s getting ♥♥♥♥ing annoying and I enjoyed playing the game very much untill now.

Systemspecs:
i5-6600K, 16GB RAM, Windows7, AMD Radeon HD 5800
Version: 45367
Build: 2/28/2017 6:19:35pm

And yes, I know the graphics card doesn´t fit very well

Edit: I just verified the game files and there was one damaged file which is now repaired. Game ran well but after I left the alien buildung to discover the island the crash occured again. I have even a new issue: Even though the game is closed, it is shown as still running in Steam. So I have to force Steam to shut down via the task manager before I can start Subnautica again.

Edit: Ok, now it´s all ♥♥♥♥♥♥ up. I have a savegame where I´m in the alien complex in front of the control room of the planetary weapon and the game crashes everytime on the hallway to the power button. Can someone please help me?! This way the game is completly unplayeable at the moment!

[Harlequin]

push

[Harlequin]

For those of you who may encounter similiar problems, here is the solution that worked for me:
I just had to force Subnautica to use Direct3D 9 instead of Direct3D 11. Guess that because of my old graphics card.

Here´s how to do it. Click on the "Troubleshooting"-window and then search for the topic "Direct3D"

http://steamcommunity.com/app/264710/discussions/0/617336568082254706/

[Phoenix]

Are your drivers up to date?