Someone messaged me last month. He had installed it three days earlier, and the devices kept flipping between offline and online. He asked whether the computer was too old.
I asked two questions. Was the cable original? He said no, he had bought a bundle of cables online because they were cheap. Was the phone plugged into a USB port on the front of the case? He said yes.
He swapped in an original cable and plugged it into a port on the back panel, and the device stayed up. Nine times out of ten, an offline device is a problem outside the software. Work from the outside in.
Cables, ports, and hubs
This layer clears more than half of the cases, and it is the fastest to check, so start here.
A lot of cheap cables carry power and no data. They look the same as a normal cable, and the computer does nothing when you plug them in. Swap in a cable you know transfers data. If that fixes it, the problem is the cable.
USB ports on the front of a desktop case are often wired through an internal adapter. Power and stability are both worse than the back panel. With few devices you may not notice. Once there are many, it shows up. Plug straight into a port on the motherboard.
When you have more devices than native ports, you need a hub. Do not use one that draws power from the computer’s USB port. With many devices, the power runs short and they drop at random. Use a hub with its own power supply, and spread the devices across different USB controllers instead of crowding them onto one bus.
Before you install, temporarily turn off antivirus, real-time protection in Windows Security, and the firewall. Turn them back on once it runs normally. Security software blocking a background service also looks like the device will not connect, and that is easy to blame on something else.
Trust, recognition, and the phone
Once the physical connection is fine, look at authorization.
When the phone is plugged into the computer, the screen asks whether to trust this computer. You have to tap trust. Some models only show the prompt after you unlock the screen, so tapping as soon as you plug in may do nothing. If you previously chose not to trust, reset it in settings.
Use a third-party phone management tool to see whether the computer recognizes this phone. If that tool sees it, the cable and driver are fine and the problem is on the software side. If it does not see it either, fix the connection first. Do not go looking inside the software.
On the phone-side main program, check all three keep-alive options and confirm the floating window is still there. If keep-alive is not active, the connection drops as soon as the phone locks. Photo library permission has to be on, or the file-transfer step fails. The input method is only needed when a task has to type on the keyboard.
If double-clicking the workstation does nothing, install the WebView2 runtime from the same folder and try again. The workstation and the phone-side program need to be signed in separately with the same account. Signing in on only one side causes device sync problems.
Devices on WiFi
Wireless dropouts are checked differently from a cable. Look at these three.
The phone and the computer have to be on the same local network. After a router change, or after the phone switches to mobile data, this is often where it breaks.
A wireless connection depends on the program on the phone staying active. If the system kills that program, the device disappears from the list.
If other devices on the same network are moving a lot of traffic, such as downloads, livestreams, or video transfer, control commands jitter and can drop. With many devices, keep the work network separate from the everyday one.
Wireless is less stable than a cable. That comes with the connection. If a few devices carry the critical work, put those on USB.
It was fine, then everything was down in the morning
These usually happen while you are not watching.
The phone installs a system update on its own. After an upgrade, the previous connection state and permission settings can all stop working. The next morning every device is wrong. Phones used for automation have to have automatic updates turned off. This one is required.
The computer sleeps or restarts on its own. The workstation runs locally. If the computer sleeps, the tasks stop. On a machine that runs long tasks, turn off sleep and automatic updates.
The phone runs out of battery. A long unattended run needs continuous power, especially for something like a video upload that drains the battery.
Let an offline device report itself
Troubleshooting happens after the fact. You can have the problem notify you first.
Set an offline alert. When a device has been offline past a set time, you get told, instead of finding out the next time you open the workstation.
Run a scheduled sweep. Use Schedule to set a task at a fixed time each day that scans device status and picks out the offline ones. You do not have to watch the screen to know which devices need attention today.
After a run, check Execution History. It has the target device, the status, and the error for each task. If one device keeps failing, do not look only at that one time. Scroll the history and see whether it has been failing all along.
A checklist you can work down
When a device is offline, start at the first row.
| Order | Check | How to confirm |
|---|---|---|
| 1 | Cable | Swap in an original or MFi certified cable |
| 2 | USB port | Use a port on the motherboard, not the front panel |
| 3 | Phone trust | Unlock the screen and tap trust this computer again |
| 4 | Computer detection | Use a third-party tool to confirm the device is seen |
| 5 | Hub power | Use a powered hub, spread devices across controllers |
| 6 | Antivirus and firewall | Disable temporarily during install and first run |
| 7 | Phone keep-alive | All options enabled, floating window visible |
| 8 | Phone permissions | Photo library granted, input method as needed |
| 9 | Workstation state | Opens, WebView2 installed, same account as the phone |
| 10 | Network, wireless | Same network, phone-side program running |
| 11 | Automatic updates | Disabled |
| 12 | Computer sleep | Disabled |
The person from the start later replaced that whole bundle of cheap cables and bought a hub with its own power supply. He has not fought a dropout since. He said that when devices drop, the cause is usually in the part that cost the least.
If you hit something you genuinely cannot trace, post a screenshot of the device page together with the error from Execution History. That is far more useful than describing it as “it just will not connect”. The install and environment notes are here.
Frequently asked questions
- A device shows offline. What is the first thing to do?
- Check the physical layer. Whether the cable is original or MFi certified, whether it is plugged into a port on the motherboard rather than a front panel, and whether the phone has been told to trust this computer. Those three account for more than half of offline cases and are the fastest to check.
- The cable still charges the phone. Why is it not detected?
- Many cheap cables carry power but no data, and look identical to a working one. The test is simple: swap in a cable you know transfers data. If that fixes it, the problem was the cable and nothing else needs touching.
- I ran out of USB ports, added a hub, and now devices drop constantly. What now?
- Almost certainly power. Use a hub with its own power supply rather than one that draws from the computer. Also spread devices across different USB controllers instead of crowding them onto one bus.
- The phone has been trusted already. Why still no connection?
- Confirm the trust prompt really went through, because some models require the screen to be unlocked first. You can also use a third-party phone management tool to check whether the computer sees the device at all. If that tool sees it, the cable and driver are fine and the problem is on the software side. If it does not, fix the connection first.
- Devices go offline again after a restart. Why?
- Two common reasons. The phone-side program is not staying alive, which usually means the keep-alive settings are not all enabled. Or the phone locks its screen and drops the connection. Enable all keep-alive options on the main program and confirm the floating window is still visible.
- How do I troubleshoot a WiFi connected phone?
- Check in order: whether phone and computer are on the same network, whether the program on the phone is still running, and whether other traffic on the network is saturating it. Wireless is inherently less stable than a cable. When you have many devices, put the critical ones on USB.
- Everything was fine overnight and all devices were offline in the morning. What happened?
- Check whether the phone installed a system update. A version upgrade can invalidate the previous connection state and permission settings together. Devices used for automation must have automatic updates disabled. That is not optional. The other candidate is the computer sleeping or restarting.
- How do I avoid finding out a day late?
- Set an offline alert so you are told when a device has been offline for a while, rather than discovering it when you next open the workstation. You can also schedule a daily sweep that scans device status at a fixed time and surfaces anything that is offline.
Get the devices stable first
Work down the checklist and most offline problems resolve
Software is completely free and runs on your own computer.