Following error message 'The application will exit because of a security problem. error: 0x20000, 0xd3',  'LowLevelFatalError [File:Unknown] [Line: 671]''LowLevelFatalError [File:Unknown] [Line: 671]' may be due to damage to the installed Dysterra client itself. 

Please reinstall the client or verify integrity of game files after deleting 'sec' folder.

[Sec folder location] 

C:\Program Files (x86)\Steam\steamapps\common\Dysterra\Content\Sec

[How to verify integrity of game files] 

1. Go to your Steam library, and right click on the 'Dysterra' app and go to properties

2. Click on local files and click on the verify integrity button