I am running Windows 11 on Parallels on my Mac Studio (15.7 and 26.0.1) in coherence mode. It has been smooth sailing for almost a year; until just this past week. Now, whenever I open an email in Outlook running on Windows in Parallels in coherence mode the email window gets clipped, only showing on existing Parallels Windows apps windows until I click on it on the edge or the info area, then it shows up in full. See the image below... When Parallels is not in coherence mode (windowed/full-screen) the clipping does not happen. I have checked outlook settings and do not see anything that could cause GFX/display issues. My Mac had been on Sequoia (15.7) for about 2 weeks when this clipping started. Parallels just notified me of an update today so I updated that and rebooted the Mac. The problem was not resolved. I thought it might be the Mac and went ahead and updated to Tahoe (26.0.1) but that also did not resolve the issue. NOTE: I did have an issue where one of the two monitors was not being detected by the Mac about 2 weeks ago. I don't think that is related but I figured I would mention it since its display related.
Following this thread. I am having the same issue. I am on Tahoe and 24H2. All of the Mac/Parallels/Windows updates have been applied. Issue still persists.
Hi, I experienced the same issue and traced it back to the KB5066835 Windows update, which is known to cause problems. After uninstalling it, the issue disappeared. I've already reported it to Parallels support. It would be great if you could do the same, as the update will eventually try to reinstall itself. A permanent solution needs to be found to prevent this from happening again. Here is a video how to uninstall the update:
It sounds like a display glitch caused by the recent macOS and Parallels updates. Since it only happens in coherence mode, try adjusting the display settings in Parallels, like resetting the scaling, turning off "Optimize for Retina," or toggling the "Always hide Mac menu bar" option. If that doesn't fix it, reinstalling Parallels Tools often clears up these kinds of window clipping issues after updates.
Hi JimA6, I've tried all of the measures you suggested. As mentioned above, the issue may be related to the Windows Update KB5066835, because an uninstall solved the issue. Reinstalling the update has resulted in the problem recurring. Did any of the steps you described help resolve the issue with your configuration? If so, which specific adjustment led to the resolution? Best regards
Greetings, Thank you for your feedback. We'd like to inform you that this is a known issue, and our Development team is actively working on a permanent fix. In the meantime, the recommended workaround is to uninstall the Microsoft Windows Security Update KB5066835 from the affected virtual machine. This has been confirmed to resolve the issue for many users while we finalize a long-term solution. Thank you!
Hi Avinash Thanks for this information. I have been experiencing the same issue. Uninstalling the Microsoft Windows Security Update KB5066835 and then reinstalling Parallels Tools has fixed the issue, at least until my machine attempts to reinstall the security update again. Hopefully you are able to deploy a long term solution very shortly. Kind regards Mark
