I am using 1.9 version on Windows 10 64 bit. My Nokia 8 and Oculus go are both in developer mode, I can use adb, I see the devices, I can install apk or fetch some file.

When I run the app without parameters or with -r, I can see that the apk is uploaded and that is all. GUI does not start and no video is recorded.

c:\bin\scrcpy-win64>scrcpy -r file.mkv
c:\bin\scrcpy-win64\scrcpy-server.jar: 1 file pushed. 0.8 MB/s (22470 bytes in 0.027s)

Logcat does not bring useful information:

08-01 09:53:35.292 17040 17040 D AndroidRuntime: Calling main entry com.genymobile.scrcpy.Server

I tried to switch off the Avast firewall and when I started the app again, the GUI was displayed. Please add a section to FAQ that the firewall may interfere with the mobile app.