regain documentation
Settings & troubleshooting
Find the active profile, resolve device ownership, and collect useful evidence when something fails.
Device missing or busy
- Close other controllers. For FocusCube3, disconnect the device in Unity; its background server can retain the serial port after the window closes.
- Check USB and external power where required. Refresh the device list and select the intended serial.
- Confirm the correct Windows driver: ZWO camera driver for cameras, HID for CAA/EFW/EAF, USB Serial Device for OFP2/FocusCube3.
- On Linux/macOS, confirm the server account has USB/HID/serial access. Do not run two frontends against the same physical device.
Alpaca is not discovered
Save the device selection first; only configured devices are advertised. Check the bind address, HTTP port, and UDP 32227 firewall access. Try the host’s address directly. Disconnect temporary setup connections before connecting your imaging application.
Settings locations
On Windows, the base is %LOCALAPPDATA%\Regain. Native NINA, ASCOM, and Alpaca selections are independent.
| Frontend | Path below the base |
|---|---|
| ASCOM cameras | ASCOM\camera-1.json through camera-4.json |
| CAA | Rotators\ascom.json or nina.json |
| EFW / EAF / FocusCube3 | Accessories\{efw,eaf,fc3}-{nina,ascom}.json |
| Alpaca cameras | Alpaca\cameras.json |
| Alpaca accessories | Alpaca\cameras.{rotator,efw,eaf,fc3,ofp2}.json |
Linux/macOS Alpaca settings use $XDG_CONFIG_HOME/Regain/Alpaca, or $HOME/.config/Regain/Alpaca. An explicit --profiles path stays as supplied. Existing ZWOgain profiles migrate without overwriting regain profiles.
Collect logs
- NINA: normal NINA logs record retry reasons, SDK fallback, cooler recovery, and final errors.
- ASCOM cameras:
ASCOM\logs. Registration failures:ASCOM\registration.log. - CAA:
Rotators\rotator.log. - EFW/EAF:
Accessories\efw.logandeaf.log. - Alpaca cameras: the
logsdirectory beside the camera profile, and the browser’s Log tab.
When reporting an issue, include regain version, OS, frontend, device model/firmware, backend, what you expected, and relevant logs. State whether the device was physical or simulated.
About the screenshots
FocusCube3 screenshots show attached physical hardware. The OFP2 image is a historical physical-device capture with the old brand. Camera, CAA, EFW, and EAF screenshots show actual interfaces using simulated devices; captions identify them explicitly. A simulator screenshot is not evidence of hardware validation.