This error is usually the result of Anti-Virus software interfering. Please ensure you have appropriate Anti-Virus and Firewall exceptions in place for Darktide.

The only other thing I can suggest is to try a Selective Startup, which can help identify whether a background application is the cause:

1. Press the Windows key
2. Type ‘msconfig’ and select ‘System Configuration’
3. On the ‘General’ tab, select ‘Selective Startup’
4. Deselect ‘Load startup Items’
5. Reboot your PC

If the issue no longer occurs after having performed the Selective Startup, try re-introducing your programs one-by-one to determine which is the culprit.

What anti-virus/firewall product are you using?

Can you fully disable both as a test?