"Device Timed Out" error in Sidecar

Apart from the list mention in https://support.apple.com/en-us/HT210380

Make sure you don't have any VPN software running and connected to a VPN. Took some time to realised that i had connected to my company vpn on my mac and a private vpn on my ipad. once I turned both off. everything started working.

After trying every suggestion I found on the web, this solved my problem:

Go to iPad settings, at the top of the menu under your apple id, there is a warning which says ''update apple id settings''.

After clicking on it and following the instructions, sidecar worked for me, wirelessly.

Hope that helps

I've been following this thread for a while as I too was having the same difficulty. I'm not sure if you were ever able to figure this out, but I just discovered that if you are connected to a network via VPN, then you will get this error. As soon as I shut down my VPN connection, I was able to get my iPad to act as a secondary monitor.

I spent some time going through several threads regarding this issue and what worked for me was not a solution that I could find anywhere. What worked for me was to go to Settings>Home Screen & Dock and make sure the check under "More" is selected. I had "Bigger" checked and as soon as I selected "More" my iPad connected immediately.

Not sure if the issue still remains for you. But in case others need solutions..

Enter in your password at System Preferences > Apple ID > Overview.

It will say that your Mac needs to update Apple ID settings in order to allow you to fully use iCloud(or Apple)'s services.

I can assume that Sidecar is definitely one of its services.

Hope this helps.

Something related to the Today View must be causing the initial time out issue. I had "do not disturb" on, turned it off, and it connected to the iPad. Turned back on do not disturb and seems to be working at the moment. This was after signing out of iCloud on both devices, rebooting and signing back it ... and it still not working. Though before signout, the option to see the iPad didn't appear at all. After signing out and back it, at least the option appeared in the Display dropdown, but then the time out issue occurred. Messing with the Today View seemed to unhitch the problem for me.

So I tried some, but not all, of the above mentioned fixes without success. I decided to try disconnecting from WiFi and as soon as I did it connected the Sidecar. Sidecar stayed connected when I connected back to WiFi. 2020 13” MacBook Pro & 3rd gen iPad Air.

This worked. Had been using sidecar then upgraded to MacOs Big Sur and it disappeared. Had to sign in and out of iCloud on iPad to get it to show. Then would just come up with time out error. Switched handoff off on both then able to connect. Good news is you can then switch handoff back on!

@ncfirechief , thank you for your advice. After working on this issue for weeks, your solution helped in combination with many of the above listed steps. I disconnected from wifi on both devices, reconnected to wifi, connected the devices via Bluetooth and the issue was resolved. I am currently typing this on sidecar. I hope it is a long-term fix. I hope this helps someone else!

I had to agree to updated terms and conditions on the iPad which was preventing it from airplay. I guess make sure your iPad is up to date and definitely on the same wifi. I have 2.4 and 5G, sometimes the devices join the alternate depending on location in my house. Good luck!

Turning off the Today View feature on the iPad worked for me.

I recently figured out that if my Macbook is connected to a VPN, it won't allow me to use Sidecar. UGH. It gives me the "timed out" error message

I tried everything on this page and none of it worked. What worked IMMEDIATELY was when I disconnected from the VPN I use to get to my work server.

Try it if you use a vpn regularly.

Making sure that both my iPad and Mac were connected to the same WiFi network solved this for me. Trivial oversight on my part.

I tried a LOT of the above suggestions. However what worked was having my iPad "Forget" the bluetooth connection to my MacBook air, and reconnecting them. THEN it finally reconnected!!!