Post work PR #701

backend/app/api/routes/virtual_printers.py

@@ -336,6 +336,20 @@ async def update_virtual_printer(
     if body.remote_interface_ip is not None:
         vp.remote_interface_ip = body.remote_interface_ip
     if body.tailscale_disabled is not None:
+        # Guard: user trying to enable Tailscale (disabled=False) must have the binary available.
+        # Otherwise the toggle looks like it works but silently falls back to self-signed.
+        if body.tailscale_disabled is False and vp.tailscale_disabled is True:
+            from backend.app.services.virtual_printer.tailscale import tailscale_service
+
+            ts_status = await tailscale_service.get_status()
+            if not ts_status.available:
+                return JSONResponse(
+                    status_code=409,
+                    content={
+                        "detail": "tailscale_not_available",
+                        "reason": ts_status.error or "tailscale binary not found",
+                    },
+                )
         vp.tailscale_disabled = body.tailscale_disabled
 
     # Auto-inherit model when switching to proxy mode with existing target printer