Deactivate all mods.

Maybe that should help.

German: Starte das Spiel ohne Mods und schau, ob das was ändert.

Hello, we are sorry you are experiencing issues with our game.
Could you please export your game log files from the launcher?

Steps on how to export logs from ARMA 3 Launcher:

1. Start ARMA 3 Launcher
2. Click the Hamburger menu tab in the launcher (Top right corner. Next to Options (Cog wheel icon) and Minimize Button)
3. Drop down menu will appear
4. Select: Prepare Arma Troubleshooting error and save those files
5. A notification will pop up with the name of the generated file

Please note that the files might take a while to collect.

Attach the generated files to the ticket. If the files are too big please use some free file sharing service.

Also, please check if your page file is enabled and how big the page file is.

How to check your page file:

1. Go to control panel
2. Select System
3. Select Advanced System settings in the left menu
4. In the new popup window select Advanced and and Click settings under Performance
5. New window will pop up. Select advanced again and check the Virtual memory tab
6. The total paging file size for all drives number represents your page file size.

Is your hardware overlocked (CPU,GPU and RAM mainly)

Lastly, we are preparing a special .EXE of the game with extended logging capability so we can identify the problem faster and with more accuracy.
Would you be able to play the game with mentioned .EXE so we can find fix for the issue faster?
This helps us investigating your problem in a big way.

Thank you for your feedback!

@Koala
Thanks for your response!
I deactivated all mods and verified the game's data files, but that didn't solve the issue either.

@Adam
Thank you very much for your response!
I checked the page file and its size is 7168 MB.
I also checked if any of my hardware components is overclocked and got to the result that that's not the case.
Additionally, I exported the troubleshooting error log following your guide. Furthermore, I got two more crash logs, which I saved after a crash respectively. Those files were indeed too big to attach to this ticket, as you said, so I uploaded them on Dropbox. Subsequent are the links to the mentioned files:

https://www.dropbox.com/s/apiq192pi381o7o/ArmaReport_Log_20151002T210701_Rops.zip?dl=0 (troubleshooting error, 7528 KB)

https://www.dropbox.com/s/yt2s8cul177e5iy/ArmaReport_Log_20150930T200051_Rops.zip?dl=0 (I guess first crash log, 1766 KB)

https://www.dropbox.com/s/n3tg8z03yxpe0d0/ArmaReport_Log_20151001T194123_Rops.zip?dl=0 (I guess second crash log, 5294 KB)

And yes, I would love to test your experimental .exe, as long as you don't collect any too personal info.

@Koala
I can't actually play my mission without the mods, so sadly that is no option.

I've had this problem ever since I bought the game about 9 days ago and submitted a ticket immediately that day. I've had maybe 6 responses from the Devs but still no fix. And I only get maybe 1 response a day with basic troubleshooting steps that I did all the very first day. I think they really should have kept this as a early alpha release still with how buggy and how many people have issues running this game on gaming computers. I play ARK Survival Evolved online and never had one single issue on that game and its still in early alpha phase. Can't believe I paid 60$ for a game that the very developers of the game have no idea how to fix the issue I'm a little upset by now sorry.

I think I found the problem.
Due to the new version of ArmA, one of my mods apparently has been partially overwritten or deleted. I just downloaded it via the Steam Workshop and the mission is playable again.