Outlook doesn't display its windows correctly in coherence mode

[johnrellis]

Since I updated from Parallels version 25 to 26.1.1, Microsoft Outlook running in coherence mode doesn't display its windows properly. When reply windows open, they either don't appear at all or they appear truncated in the window frame of the main Outlook window. The drop-down menus from the top menu bar of the message windows gets truncated at the window's boundary rather than extending out past it. (Screen shots attached.)

How do I roll back? This is fairly disruptive. (I usually wait for the .1 release before updating to a new major version, but next ext year, I'll wait for the .2 release.)

Mac OS 15.7.1 / Mac OS M2 Max (Apple Silicon)
Parallels Desktop for Mac Pro 26.1.1
Parallels ARM Virtual Machine
Windows 11 Pro, Version 24H2, OS build 26100.6899, Windows Feature Experience Pack 1000.26100.253.0
Microsoft Outlook for Microsoft 365 MSO (Version 2510 Build 16.0.19328.20082) 64-bit

Updating to Mac OS 26 isn't an option yet, since Adobe Lightroom Classic 14 isn't certified to run on it and I'll want to wait at least a month after Lightroom Classic 15 arrives next week before upgrading Mac OS 26.

 

[johnrellis]

Oops, the Windows version is actually:

Windows 11 Pro, Version 25H2, 26200.6901, Windows Feature Experience Pack 1000.26100.253.0

(I looked at the wrong VM.)

 

[JonathanP24]

Several of the users on my team are experiencing the same issue. Has anyone made any progress on a solution?

 

[ImraanN]

Hello @johnrellis and @JonathanP24 ,

We've identified this as a known issue introduced by the latest Windows 11 update. Our development team is already working on a fix.

As a temporary workaround, please uninstall the Microsoft Windows (KB5066835) Security Update. After uninstalling, we recommend pausing Windows updates for 1-5 weeks to prevent this update from reinstalling until a permanent fix is released.

To stay informed about official fixes, we encourage you to subscribe to our release notes.
Click Get updates on that page to receive notifications when new versions, including potential fixes, are released.

Thank you.

 

[johnrellis]

@ImraanN ,

I uninstalled KB5066835 and now Outlook is working properly again in coherence mode in 26.1.1. Thanks much.

 

[Shawn_N]

I also uninstalled KB5066835 and now Outlook is working properly again.
BUT...
I currently have Windows Update on pause for 5 weeks. @ImraanN do you think it will be fixed by then? Not good to disable important security fixes for too long! But happy for now there's a short term fix. This was driving me crazy!

 

[NadymS]

Hello @johnrellis and @JonathanP24 ,

We've identified this as a known issue introduced by the latest Windows 11 update. Our development team is already working on a fix.

As a temporary workaround, please uninstall the Microsoft Windows (KB5066835) Security Update. After uninstalling, we recommend pausing Windows updates for 1-5 weeks to prevent this update from reinstalling until a permanent fix is released.

To stay informed about official fixes, we encourage you to subscribe to our release notes.
Click Get updates on that page to receive notifications when new versions, including potential fixes, are released.

Thank you.

Unfortunately I might be a bit late in the game. Windows doesn't allow me to uninstall that particular update anymore.
Thus, I am stuck with that bug which really decreases productivity.

Is there a solution on the horizon? I hoped that today's update to 26.1.2 would solve it, but it didn't
Best, Nadym

 

[Shawn_N]

Unfortunately I might be a bit late in the game. Windows doesn't allow me to uninstall that particular update anymore.
Thus, I am stuck with that bug which really decreases productivity.

Is there a solution on the horizon? I hoped that today's update to 26.1.2 would solve it, but it didn't
Best, Nadym

I had to uninstall these updates before I could see KB5066835 in the uninstall list:

• Update for Microsoft Windows (KB5066128)
• Feature Update for Windows 11 25H2 via Enablement Package (KB5054156)

Still waiting to hear back from Parallels on an ETA for a real long-term fix here. Hopefully they will let us know soon. It's a painful bug!

 

[HC_3]

I'm having the same problem here (macOS 15.7.1, Windows 11 Pro 24H2, Parallels Desktop 26.1.2).

And I can't find KB5066835
Nor can I find KB5066128 or KB5054156 ((
When were the three updates released?

Who can help?

 

[Shawn_N]

FYI: Parallels just released Desktop 26.1.2 (build 57293) today, but the official release notes only say it "addresses overall stability and performance issues" with no mention of the Outlook/Coherence rendering bug described in this thread.
https://kb.parallels.com/131014

Can someone from Parallels please state clearly and unambiguously whether 26.1.2 includes a fix for the Outlook windows not displaying correctly in Coherence mode with KB5066835?

Right now, the only guidance we have is a temporary workaround that involves removing recent Windows security updates and pausing Windows Update for multiple weeks. That is not a reasonable long‑term solution for people who rely on Outlook all day and also need to keep their systems properly patched.

Several of us here have opened support tickets and have been dealing with this for a while, with very slow responses and no published ETA. This is a major productivity issue for paying customers, and the current level of silence/ambiguity is really frustrating. Clear communication from Parallels about what 26.1.2 does or does not fix (and when a proper fix is coming) would go a long way here.

Tagging @ImraanN and other Parallels staff here, since you previously acknowledged this as a known issue and recommended the current workaround.

 

[JonathanP24]

Any further updates here? Still having this issue

 

[VoidB]

You're not dreaming; it sounds like a Coherence bug in 26.1.1. The simplest workaround is to update the Outlook/Windows graphics drivers inside the virtual machine (VM) or quit Coherence. To roll back, use the "Previous Versions" tab in your Parallels account to remove version 26 and reinstall version 25.

 

[Shawn_N]

Any further updates here? Still having this issue

It's crazy to me that we have received NO response from Parallels about this. Are we the only people using their product these days?

 

[CoreyM2]

I'm having this same issue but only when I have an external monitor connected. Is that what everyone else is experiencing? When I move back to my MacBook screen the windows aren't cut off.

 

[Shawn_N]

Great news! Parallels just released an update which fixes this issue: Mac 26.2.0 (57363).
The update page specifically says: "

• Fixes the issue that caused MS Office 365 windows to disappear when a Windows 11 25H2 virtual machine is switched to Coherence mode. [https://kb.parallels.com/131014/]

I installed this update, applied all the latest Windows patches, and I do not see the bug anymore.

This is great, BUT...

Parallels lack of communication here is very concerning. Why do more and more companies feel like it's ok to ghost their customers like this? Why am I the one updating this thread and not an employee of Parallels? Do they not have any support people anymore? Do they not care? I don't get it.
I feel like all I can do is leave my rant here and maybe, hopefully, an exec might see this and actually do something about the horrible support here.

 

[滝江成吉]

最新のバージョン26.2.0 (57363)では、バージョン 26.1.2 (57293)までのWindows 11, version 25H2に起因するいくつかの問題は確かに改善されてます。
しかしながら、この最新バージョンの26.2.0 (57363)では、拡張ディスプレイに接続せず、mac単体でcoherenceモードでスタートメニューを何度か表示すると、
突然スタートメニューのみ突然別のウインドーに移動するバグが新たに発生してます。
また、スタートメニューの枠の周りに、変な隙間が表示されてるのは、以前のままです。
運営側へ報告はしてますが、まだ改善方法は見えてません。

 

[GlenP1]

FYI: Parallels just released Desktop 26.1.2 (build 57293) today, but the official release notes only say it "addresses overall stability and performance issues" with no mention of the Outlook/Coherence rendering bug described in this thread.
https://kb.parallels.com/131014

Can someone from Parallels please state clearly and unambiguously whether 26.1.2 includes a fix for the Outlook windows not displaying correctly in Coherence mode with KB5066835?

Right now, the only guidance we have is a temporary workaround that involves removing recent Windows security updates and pausing Windows Update for multiple weeks. That is not a reasonable long‑term solution for people who rely on Outlook all day and also need to keep their systems properly patched.

Several of us here have opened support tickets and have been dealing with this for a while, with very slow responses and no published ETA. This is a major productivity issue for paying customers, and the current level of silence/ambiguity is really frustrating. Clear communication from Parallels about what 26.1.2 does or does not fix (and when a proper fix is coming) would go a long way here.

Tagging @ImraanN and other Parallels staff here, since you previously acknowledged this as a known issue and recommended the current workaround.

I'm actually running into something very similar after updating, and I have the same question about rolling back because it's been pretty disruptive. The coherence mode glitches you're describing sound almost exactly like what I'm seeing windows not showing up properly and UI elements getting cut off. It makes Outlook really frustrating to use day-to-day, especially when replying to emails.

I also tend to wait for more stable releases, but this one still seems to have slipped through with some issues. I haven't found a clear rollback path yet either, so I'm really hoping someone here can share the proper way to revert to the previous version without breaking the VM setup. Would definitely appreciate any guidance or workarounds others have found in the meantime.