Workstation 26H1 Tabbing changes fullscreen to thumbnail

[Derek Logie]

When switching from an active VM to the HOME tab, and then back to the VM leaves the display as a thumbnail. 

I have to use View/Full screen and then Exit Full screen to get the active VM back to its normal size. Is there a parameter/option making this happen?

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Derek Logie
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[HansJoachim Ballin]

Hello Derek, less of information you provided.
Just for information, I also upgraded to 26H1 yesterday, and everything works fine. I also applied your instruction for the failure picture, all work good on my end.

I'm using Win 11 as a host, as well as a Win 11 in the VM itself with the latest Vmware tools installed.

-Hans

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[Derek Logie]

I am using Win10 (with extended support).  I de-installed/re-installed and the issue still exists. I have regressed to Workstation 2025H2u1 and it is working as expected again.

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Derek Logie
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[bevanweiss]

I've seen this same behaviour in several of my linux guests.

I found that if I enabled the Graphics Acceleration options for the guests the problem went away.  So potentially it's related to the software-based graphics driver.

Can you try the same and report back?

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[Derek Logie]

Ok - I'll back up my laptop then try again. I also installed 2026H1 on my Windows laptop, and that worked fine. What I did notice is that my Windows 11 laptop is using the Microsoft Hypervisor, but my Windows 10 laptop does not have this enabled and is using the  inbuilt VMware version, so that is another difference.

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Derek Logie
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[Matt James]

@bevanweiss My setup Win11 Host and Win11 Guests, now work fine after I enabled the Graphics Acceleration options. Thanks..

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[Mateusz Cichon]

Seeing identical behavior here. Windows 11 25H2 (26200.8457) as host and Debian 12 as guest, Guest Tools irrelevant since it happens even before system can boot (ie. GRUB screen). Enabling 3D acceleration fixes it, though obviously that is not a perfect solution long-term. Note I have multiple GPUs (one discrete, one integrated) on this PC so this might be one of causes.

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[Dhairya Tomar]

Mateusz Cichon Derek Logie bevanweiss Requesting you to recreate the issue and share video of the same and also share full support bundle of the affected VMs.

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[Mateusz Cichon]

I have isolated the issue down to a stale preference

pref.remoteMKSHardwareAccel = "TRUE"

I could not find information on what it does, though considering this installation of VMWare remembers time when Workstation could access remote servers, it might be related to that. Removing this preference solves issue for me.

I was unable to create support bundle as I was met with error: "There is no script engine for file extension '.js'"

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[Step Joint]

I verified that the parameter was not present in my .vmx configuration by default. However, after manually adding the following entry:

pref.remoteMKSHardwareAccel = "FALSE"

the issue was resolved.

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[Derek Logie]

I started noticing other strange display related isssues in my Linux VM (host = Win11). One obvious one was the screen would go blank when tabbing around- to fix it I did a suspend/resume and it was back to normal. Had this twice now, so I have regressed to 2025H2u1.

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Derek Logie
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[Jim954]

I have same issue.  upgraded from 25H2 to 26H1. As well as a 26H1 repair just to see if that was an install issue. Was not.
The thumbnail problem exists with Linux or Windows guests for me.
This issue seems to be a focus problem relating to current window size.
If I increase/decrease size in any way it will snap back to current size, but...depends on view stretch settings on/off or type. 

In any event there is a bug here. I have been a VMware user for over 15 years. This is a first time seeing this type of focus problem.
I have over 40 guest systems and am not going to be fiddling with each display settings.

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[Jim954]

I found a work-around for my system.
shutdown or pause all Guests.
Open Console Menu | Edit | Preferences | Display
UnCheck "Allow hardware acceleration for all virtual machine consoles."

Close GUI Console and reopen for changes to take effect.

I do not know the individual effect of doing this, but for my guest systems I don't think accelerated graphics is needed.

Regards
Jim954

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[Dhairya Tomar]

Jim954Step JointMateusz Cichon and other affected users,Requesting you to recreate the issue and share video of the same and also share full support bundle of the affected VMs.

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[Claus Boerschig]

I would like to contribute:

After a great deal of hesitation due to numerous issues, I installed 26H1 on my notebooks.

One is a new Dell Precision 7780 featuring Intel UHD Graphics and an NVIDIA RTX A1000 Laptop GPU.

The other is an older HP ZBook with Intel HD Graphics 4600 and an NVIDIA Quadro K2100M.

I am running several virtual Windows Servers and appliances, such as StoreOnce and Data Domain.

Following the installation, the checkbox under Preferences > Display > "Allow Hardware Acceleration for all Virtual Machine Consoles" was enabled.

On the Dell system, using "tabbing" causes graphics crashes within the consoles-including the text-based consoles for the appliances. Tabbing works correctly on the HP system.

On both devices, however, everything functions properly if hardware acceleration is globally disabled.

Adjusting settings for individual VMs has no effect.

Greetings Claus

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[Dhairya Tomar]

Raised a ticket internally, relevant team will look into the issue.

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[Frank Schmidt]

I am also experiencing display issues following the update to VMware Workstation 26.0.0.25388281 and VMware Tools 13.1.0.0.25218885.
Disabling 3D acceleration improves the situation, though occasionally the guest system still fails to display, showing only a black screen.
Resizing the window causes the VM to appear-or not-depending on the specific window dimensions. However, switching to full-screen mode results in a black screen once again.
The host system is Windows 11, and the problem affects all guest systems (Windows 11, Ubuntu Linux 24H2, Linux Mint 22.3).
I can provide a video via email, though I would prefer not to post it publicly here.

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[Claus Boerschig]

I confirm, same situation here.

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[Travis Castor]

I am experiencing the same issue, thought it was just me. I have turned off hardware acceleration globally for now, immediate results seem to be good. But we'll see how it holds up.

[sininspira]

Same boat. Remote host is vSphere 7/ESXi 7, latest open-vm-tools-desktop. Turning off global hardware acceleration on my Workstation 26 client fixed the issue for me.

[Amelius Jan van Twillert]

I have the same issue here. Also thumbnail size. And thats really small on 1/3rd of my 49" screen. sometimes after just moving the application from 1/3rd of my screen to just somewhere else the resolution changes back to a viewable size.

[tuaris]

In case anyone needs to see the issue manifest itself, this happens when you switch between tabs or open a remote console from vCenter.  Resizing the Window 'fixes' it temporarily until you switch tabs again.  That only works if you have a guest OS with VMware tools.

The workaround is (as was suggested in this tread) to disable hardware acceleration on the VMWare Workstation instance.

This issue only appeared after upgrading to 26.0.0.25388281.  Any version prior to VMware® Workstation Pro 26H1 does not have this problem.  It's clearly some kind of regression.

[AEglinton]

I had this issue immediately after upgrading to 26H1. It appears to be more of a focus issue rather than simply a VM switching issue. 

I have a 3 monitor setup and if I have 3 VMs running, one on each monitor, and just switch between them, then I don't see the issue. If I have the same VMs running on the same monitor and then tab between them, then I get the issue. As has been mentioned simply switching out of full screen clears the issue and you can switch back to full screen again. Interestingly enabling 'Accelerate 3D Graphics' in the individual VM does solve the problem but then so does the 'disabling Hardware Acceleration' fix, which seems counter intuitive as you seem to be doing opposite things.

Enabling the 3D acceleration, for me, creates the issue of losing the VM tab bar at the top of the screen in Win11 VMs, which is irritating so for now I am running with the disabling Hardware Acceleration workaround and all appears to be working fine for now.

My host Win11 25H2, AMD Ryzen 5950, NVidia RTX4070TI.

VMs WIN11, WIN10 and WIN7, all show the same behaviour.