macOS Tahoe broke your Microsoft apps: every known issue (June 2026).

Teams keeps asking for location permission on Mac.

This is a confirmed Microsoft incident, TM1315837, active since around May 14, 2026, caused by a macOS security update, not by Teams. The dialog reads "Microsoft Teams ModuleHost would like to use your current location" and comes back no matter how many times you click Don't Allow.

Cause

Microsoft's incident report says a recent macOS security update stops the operating system from saving the location permission choice for Teams, so Teams asks again every time it checks. It affects macOS 14 Sonoma, 15 Sequoia, and 26 Tahoe, and only users who turned on location access inside Teams settings. Microsoft is working with Apple on the OS side and on a Teams-side mitigation in parallel, per the incident posted to the Microsoft 365 Admin Center in May 2026.

The workaround that stops the prompts

1. Quit Microsoft Teams completely. Right-click the Teams icon in the Dock and choose Quit.
2. Open System Settings, then Privacy & Security, then Location Services.
3. Find Microsoft Teams and Microsoft Teams ModuleHost in the app list.
4. Toggle both entries off, wait a few seconds, then toggle both back on.
5. Set each toggle to the state you actually want, then relaunch Teams.

This is Microsoft's published workaround and it may need repeating until the permanent fix ships. If you do not need Teams location features such as emergency calling location, you can also turn off location access inside Teams settings so there is nothing left to prompt about.

Outlook crashes when you open or create a calendar event on Tahoe 26.5.1.

Since early June 2026, Outlook for Mac 16.109 crashes the moment you double-click a calendar slot or event on macOS Tahoe 26.5.1, and reinstalling does not help. Microsoft Q&A and Tech Community threads from June 2 to 6, 2026 confirm the same crash signature across users: EXC_CRASH (SIGTRAP) blaming the OlkCalendarUIKit module.

Cause

The crash reports point at the calendar UI module in recent Outlook builds, surfacing after the late May 2026 Office update on Macs that took the Tahoe 26.5.1 update. Users in those threads report that reinstalling Outlook, clearing caches, and safe mode all fail, because the broken code path is in the build itself. Mail keeps working, and the same account's calendar is fine on phones and on the web, which confirms the data is intact.

Work around it until Microsoft ships the fix

1. Do not double-click the calendar. Right-click the time slot or event instead and use the context menu to create or open it. The double-click handler is the broken path; the context menu route works.
2. If right-click also crashes on your build, use the New Outlook toggle to switch to the legacy Outlook client temporarily. The legacy calendar code is unaffected.
3. For anything urgent, manage the event at outlook.office.com in a browser. Your calendar database is fine; only the desktop UI path crashes.
4. Keep running Microsoft AutoUpdate (open Outlook, choose Help, then Check for Updates). The permanent fix arrives as an Outlook build update, so do not freeze updates.

Word, Excel, PowerPoint, or Outlook crash or vanish on Tahoe.

Most Office crashes on Tahoe, reported since its September 15, 2025 release, resolve with an app update or a clean reset of Office's local files. Apple Support Communities threads from October 2025 describe apps quitting silently with nothing in the crash log, and Microsoft Q&A threads as recent as February 2026 (on Tahoe 26.3) show launch crashes that survive a plain reinstall.

The ladder, in order

1. Update Office first. Open any Office app that still works, choose Help, then Check for Updates, and install everything Microsoft AutoUpdate offers. Microsoft ships Tahoe compatibility fixes through app updates, so an outdated build is the most common cause.
2. Update macOS. System Settings, General, Software Update. Point releases have fixed several Tahoe app issues since launch.
3. Outlook only: hold Shift while launching to start it in a reduced state and rule out a corrupt window layout.
4. Reset preferences. Quit the app, open Finder, press Cmd+Shift+G, go to ~/Library/Preferences, and move the matching com.microsoft.* files to your Desktop. Relaunch; macOS rebuilds fresh ones.
5. Clean reinstall. Delete the Office apps from Applications, then in ~/Library/Group Containers remove the folders that begin with UBF8T346G9, empty the Trash, restart, and reinstall from office.com. Warning: this signs you out of Office on this Mac and clears local caches and settings. Microsoft 365 accounts re-download mail and settings after sign-in.
6. Isolate the profile. Create a new macOS user account in System Settings, Users & Groups, and launch the app there. If it runs clean, the problem lives in your user profile, not in Office or Tahoe.

If the apps run fine in a new user account, a Vision session is exactly the kind of cleanup Anthony does well: finding the corrupt cache, login item, or extension in your profile without nuking the whole account.

Microsoft 365 apps will not open after a macOS security update.

macOS security updates have broken Microsoft apps twice in 2026 alone: the May update behind the Teams location loop (incident TM1315837) and the 26.5.1 update tied to the Outlook calendar crash in June. So if an app stopped launching right after you installed an update, suspect the update first, and check whether you are looking at a known incident before deep surgery.

Run this in order

1. Restart the Mac once. Security updates sometimes finish their housekeeping on the next boot, and a surprising number of post-update launch failures end here.
2. Check for a known incident first. Look at Microsoft's fixes and workarounds for recent issues in Outlook for Mac page, and your admin can check Service health in the Microsoft 365 admin center. If it is a known incident, the fix is usually a workaround plus patience, not a reinstall.
3. Update everything Microsoft. Help, then Check for Updates, in any Office app. Compatibility fixes for new macOS builds ship here.
4. Confirm you are still in the support window. Microsoft supports Office and Teams on the three most recent macOS versions only. As of June 2026 that is Tahoe 26, Sequoia 15, and Sonoma 14. Older versions stop getting updates and eventually stop launching current builds.
5. After a major upgrade, check the Moved Items folder. Tahoe relocates incompatible components there during upgrades. If Microsoft helper items landed in it, reinstall the affected app.
6. Still stuck: run the crash ladder above, from preference reset through clean reinstall and the new-user-account test.

Teams will not run on macOS Ventura or older.

Microsoft supports the Teams desktop app on the three most recent macOS versions only: Tahoe 26, Sequoia 15, and Sonoma 14 as of June 2026. Ventura 13 and older are out of support. Ventura users started reporting "The application 'Microsoft Teams' can't be opened" after a Teams update in early February 2026, and Microsoft moderators confirmed the OS had dropped off the support list, citing the official Teams client system requirements.

Your three options

1. Upgrade macOS if the hardware allows it. The upgrade is free: System Settings, General, Software Update. This is the only way to keep the Teams desktop app.
2. Use Teams on the web at teams.microsoft.com in Safari, Chrome, or Edge. It covers chat, meetings, and calls while you plan the upgrade.
3. Plan the hardware replacement if the Mac cannot reach Sonoma 14 or later. A Mac stuck below the support window will keep losing Microsoft apps one by one, because the same three-version policy applies to Word, Excel, PowerPoint, and Outlook updates.

When it is not your Mac.

Three honest exclusions. If the same account fails on every device, it is a Microsoft 365 service or account issue, not the Mac, so check service health before touching the machine. If the issue is one of the two open incidents above, the real fix ships from Microsoft or Apple, and anything beyond the workaround is wasted effort. And failing hardware, a dying SSD or bad RAM, can masquerade as app crashes; frequent crashes across non-Microsoft apps too point there.

Or let Anthony fix it in a Vision session.

Everything on this page is work Anthony AI performs autonomously through Vision remote support, inside the Microsoft Teams chat your company already uses. You paste a one-time code generated on your own Mac, you watch every click and keystroke live, every action is logged back to the chat, and the session caps at 20 minutes. Full macOS and Windows parity, which matters here, because most small-business IT options barely touch Macs.

Sources.

Microsoft 365 Admin Center incident TM1315837, posted May 2026, repeated location prompts in Teams for Mac. · BleepingComputer coverage of TM1315837, May 2026. · Microsoft Q&A: Outlook calendar crashing after upgrading to macOS Tahoe 26.5.1, June 4, 2026. · Microsoft Tech Community: New Outlook for Macintosh calendar crashing, June 2026 (crash signature, OlkCalendarUIKit). · Microsoft Q&A: Teams fails to launch on macOS Ventura after recent update, February 5, 2026. · Microsoft Teams client system requirements, learn.microsoft.com, accessed June 12, 2026. · Fixes or workarounds for recent issues in Outlook for Mac, support.microsoft.com, accessed June 12, 2026. · Apple Support Communities: Microsoft 365 crashes after Tahoe update, October 2025. · Microsoft Q&A: Outlook app crashing on Mac (Tahoe 26.3), February 24, 2026.