I have tried to resolve this issue with Windows support but they have no solution so far and the months pass by... so I would like to try here and see if some smart member(s) on Superuser can help me out!
I have an Acer laptop with 1 TV and 2 external monitors connected. (4 screens in total, laptop internal, 2 external and TV). The TV is connected directly via the laptops HDMI and the 2 external monitors are connected via an USB hub with its own gfxcard.
I have the internal laptop monitor set to "Disconnect this display" while the others are connected. The internal display is only used when all other monitors are disconnected. So I use 3 screens, the 2 external monitors and the TV. Like in the image below:
These are not my screens, just a pic I found on the web to describe the setup.
ISSUE:
I get this popup with error message in Windows 10 every time I turn off or on the TV, I it have connected to my laptop via HDMI.
A toolbar is already hidden on this side of your screen.You can have only one auto-hide toolbar per side.
This is what happens:
When I either turn on or off the TV the other monitors flash and I hear the the blip-blop sound of disconnecting a device. Right after it happens the taskbar that I have set to Auto-Hide is suddenly popping up, is visible and does not hide again. This is irritating because I like taskbar to always Auto-hide. But most irritating, a warning sound and a popup appears with the error message:
A toolbar is already hidden on this side of your screen.You can have only one auto-hide toolbar per side.
My TV turns itself off after a while to save energy and PLOPP I get the fricking popup again. Often in the middle of doing something that gets interrupted until I click OK on the popup.
I have tried searching internet for a solution or for someone with same or even a similar problem, but incredibly I could not find anything at all related. The issue is extremely irritating because I turn on and off the TV several times every day. And each time I have to close the popup and then enter taskbar settings and change it back to auto-hide.
To make things even worse the popup with the error message is sometimes showing only on the turned off TV connection so that I have to turn on the TV again and click OK on the popup to be able to access the taskbar at all again.
I got a few replies from a guy at Microsoft with suggestions, but nothing that worked or was even close to work, you can read it here: https://answers.microsoft.com/en-us/windows/forum/windows_10-other_settings/a-toolbar-is-already-hidden-on-this-side-of-your/77239fea-635a-4fea-8c48-2128361303ec?messageId=ca5d7e4b-c274-4932-a236-4e2b3a927483
I would very much appreciate any help in this matter as it is slowly driving me crazy...
Thanks in advance!
EDIT:
(April 2020) The problem disappeared. I can only imagine that a Windows update did something to fix it, but I have not clue what or when. It just stopped happening.
(August 2023) It came back when I bought a new computer. Now Im on Windows 11 and the same issue occurs from time to time with no logical explanation.
So the issue is still unsolved.