# Troubleshooting Start with two things: update **every** device you pair to the same version, and look at **General › Advanced › Engines in use**, which says what this session runs on and why a faster path isn't in use. For a bug report, attach the log: **Open log folder** in the tray or menu bar menu. ## Devices don't find each other - **Same network?** Discovery is UDP **47801** and the session is TCP **47800**. Guest Wi-Fi, office Wi-Fi and some routers ("AP isolation", "client isolation") block devices from seeing each other. Bluetooth, a phone's hotspot or a USB cable still work, and so does **Connect by address** (Connection) with the other computer's IP. - **Windows firewall.** Allow TwinDesk when Windows asks. If you missed it, Setup's firewall check fixes it. Windows marks most new Wi-Fi networks as Public, and TwinDesk's rule covers every profile. - **Linux firewall.** Setup's firewall fix opens TwinDesk's ports and mDNS (5353/udp). With firewalld blocking inbound UDP, discovery and the fast input lane can't get in. - **"Port 47800 is in use".** Another program holds the port. On Windows with **WSL2**, a program inside WSL can hold it without showing in Windows' `netstat`: run `wsl -e sh -c 'ss -lntup | grep 478'`, or `wsl --shutdown`. TwinDesk tries the port again every 10 seconds (#124). - **Away from home.** Put both devices on the same Tailscale tailnet. TwinDesk reaches a paired computer through it when discovery can't see it (#161). - **"looks different now".** The other device was reinstalled or reset, so its certificate changed. Forget it (Connection › Forget) and pair again. ## Pairing fails - **Locked out.** Five failed or cancelled pairings from one address within 10 minutes lock it out for the rest of the window. Wait, then try again. - **Version mismatch.** Update the side that's older. The message says which. - **One UI (Samsung), wireless debugging.** The pairing code changes when you leave the dialog. Type it while the dialog is still open (#32). ## Mouse and keyboard - **Mac: nothing moves.** Grant **Accessibility** and **Input Monitoring** in System Settings › Privacy & Security, then quit and reopen TwinDesk. After an update that reset them, the Setup screen shows which ones are missing. - **Linux on Wayland: nothing moves.** Run Setup's **Fix** for input access, then log out and in. General › Input access shows the state. On distros with glibc older than 2.32, update to 2.5.3 or later (#149). - **The pointer comes back by itself.** **Shake to bring the pointer back** may be catching fast moves. Turn it off on the Cursor page (#155, #160). - **Quick flicks cross to the other computer.** Turn on **Edge resistance** on the Cursor page. - **The pointer crosses at the wrong place.** Arrange the monitors on the Cursor page's map (in Multi-device, on the Multi-device page) to match your desk. - **Stuck on the other computer.** Double-tap **Right Alt** (Right Option on a Mac), the hotkey, to bring everything home. - **Wrong keys or symbols.** Each side types in its own keyboard layout. If a layout still comes out wrong, open an issue with both layouts named (#10). - **An Android phone types QWERTY on an AZERTY (or other) keyboard.** Turn on Phone › Settings › **Type as a hardware keyboard** (needs wireless debugging; in Multi-device too). Then on the phone, Settings › System › Keyboard › Physical keyboard › **TwinDesk keyboard**, pick your layout. Accents, dead keys and AltGr symbols come out as they do on that keyboard (#123, #188). - **Windows: a UAC prompt or the lock screen.** Windows keeps these on a secure desktop that no normal app can reach. Use the computer's own mouse for that prompt (#210). ## Screens - **Black screen, "Waiting for the picture".** On Windows, turn off the **hardware encoder** (Share screen › Picture) and try again (#133). Codec **H.264** works everywhere, H.265 needs both sides to support it. - **Extend isn't offered.** Windows needs the virtual display driver (Share screen installs it). Windows on ARM can't load it (#14). On Linux, GNOME on Wayland uses Mutter's virtual monitor, KDE Plasma on Wayland uses krfb-virtualmonitor, and X11 needs a spare output (not on NVIDIA's driver). - **Linux: the screen picker keeps opening.** Pick the screen, or "Virtual remote monitor" for Extend, and press Share. - **The share stopped after locking the computer.** It comes back on unlock. Update if it doesn't. ## Files and clipboard - **Slow files.** Engines in use should say **fx2**. Over Bluetooth, TwinDesk moves big transfers to Wi-Fi Direct by itself. For the most speed on a network you trust, turn off **Files › Encrypt file transfers** on both sides. - **Linux on Wayland: the clipboard doesn't sync.** TwinDesk uses `wl-clipboard`. Install it (`wl-copy`, `wl-paste`) if your distro doesn't have it. - **Mac: pasting waits a moment.** That's Universal Clipboard fetching from another Apple device. It no longer delays TwinDesk (#211). - **Passwords don't sync.** On purpose: entries a password manager marks as private are skipped. ## Android phone - **Play Protect blocks the APK.** Tap **More details › Install anyway**. Where there's no such button, pause **Scan apps with Play Protect** in the Play Store while you install, then turn it back on, or let the computer install it over wireless debugging. - **Notification access or Accessibility greyed out.** Settings › Apps › TwinDesk › ⋮ › **Allow restricted settings**. - **The screen shows but taps do nothing (Xiaomi, Redmi, POCO).** Turn on **Developer options › USB debugging (Security settings)**. - **Wireless debugging keeps turning off** (MIUI, HyperOS). TwinDesk turns it back on when the phone is unlocked. Keep TwinDesk allowed to run in the background (General on the phone). - **The phone doesn't reconnect after Wi-Fi was gone a while.** Update both sides to 3.1 (#192). - **Gesture navigation stopped working.** Update to 2.4 or later (#67, #118). ## Antivirus warnings Unsigned installers, input hooks and a virtual camera look like malware to some heuristics. TwinDesk is built in the open by GitHub Actions from this repository. A detection on `TwinDesk-Setup-*.exe` or `twindesk-vcam-*.dll` is a false positive (#12, #111). Allow it, or build it yourself from source. ## Still stuck [Open an issue](https://github.com/InukaAsith/TwinDesk/issues/new/choose) with the versions and platforms of both devices, what you did, what happened, and the log from Open log folder.