Outlook for Mac freezes after switching to the new editor

Question

Outlook for Mac freezes after switching to the new editor

Gershon Goldenberg 10

Hello,

Outlook for Mac freezes only when replying to an email (Reply). When typing the first character in the reply window, CPU spikes to 99% in multiple “Microsoft Outlook Web Content” processes, and the editor hangs. Creating a brand-new email works normally. The issue appears only in the separate compose window with the new editor.

Thank you,

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Gershon Goldenberg 10 Reputation points

2025-12-10T20:16:08.9+00:00

This is not a general performance issue.

It is a reproducible BUG in the new Outlook for Mac editor, and it happens ONLY when replying to emails.

Typing the first character in a Reply window causes CPU to spike to 99% in multiple “Microsoft Outlook Web Content” processes and the editor freezes.

New emails work fine.

I already provided videos, CPU evidence, diagnostics, and an Incident ID.

I am also in contact with Contact Support, but they reply once every 5 hours — this is unacceptable for a critical issue affecting normal work.

Please stop sending generic suggestions and escalate this to engineering immediately.
Anonymous

2025-12-11T04:38:58.9966667+00:00

Hi @Gershon Goldenberg

Thank you for posting your question in the Microsoft Q&A forum.

We understand how frustrating it can be to wait several hours between support responses, especially when a critical feature like replying to emails isn’t working and is impacting your productivity. Thank you as well for providing detailed information and screenshots; they are extremely helpful in understanding the issue clearly.

As community moderators, we don’t have access to Outlook’s internal diagnostics or engineering tools, so our ability to troubleshoot issues like this is limited to public documentation and what other users have reported. Since you’ve already opened a support case and provided an Incident ID, you’ve taken the right step to get this properly investigated.

We completely understand how disruptive this situation is, and it’s absolutely reasonable to expect timely updates. The support team is the group that can review logs and escalate this issue directly to engineering. Continuing to follow up on your case will help ensure the issue receives the right level of attention.

We truly appreciate your patience and understanding, and we hope the support team can identify the root cause quickly so you can return to a smooth workflow.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

2 answers

Gershon Goldenberg 10 Reputation points

2025-12-10T20:16:08.9+00:00

This is not a general performance issue.

It is a reproducible BUG in the new Outlook for Mac editor, and it happens ONLY when replying to emails.

Typing the first character in a Reply window causes CPU to spike to 99% in multiple “Microsoft Outlook Web Content” processes and the editor freezes.

New emails work fine.

I already provided videos, CPU evidence, diagnostics, and an Incident ID.

I am also in contact with Contact Support, but they reply once every 5 hours — this is unacceptable for a critical issue affecting normal work.

Please stop sending generic suggestions and escalate this to engineering immediately.
Anonymous

2025-12-11T04:38:58.9966667+00:00

Hi @Gershon Goldenberg

Thank you for posting your question in the Microsoft Q&A forum.

We understand how frustrating it can be to wait several hours between support responses, especially when a critical feature like replying to emails isn’t working and is impacting your productivity. Thank you as well for providing detailed information and screenshots; they are extremely helpful in understanding the issue clearly.

As community moderators, we don’t have access to Outlook’s internal diagnostics or engineering tools, so our ability to troubleshoot issues like this is limited to public documentation and what other users have reported. Since you’ve already opened a support case and provided an Incident ID, you’ve taken the right step to get this properly investigated.

We completely understand how disruptive this situation is, and it’s absolutely reasonable to expect timely updates. The support team is the group that can review logs and escalate this issue directly to engineering. Continuing to follow up on your case will help ensure the issue receives the right level of attention.

We truly appreciate your patience and understanding, and we hope the support team can identify the root cause quickly so you can return to a smooth workflow.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 1

Gershon Goldenberg 10

I wanted to update that the issue has been resolved.

I removed both Outlook applications, deleted the related Group Containers and preference files, restarted the Mac, and reinstalled Outlook from the App Store. After reconfiguring my accounts, Outlook is now working smoothly with no freezes when replying to emails.

Thank you,

Anonymous

2025-12-11T13:16:50.2966667+00:00

Hi @Gershon Goldenberg
Thank you for your update. Your detailed input will be incredibly valuable for others who might encounter the same challenge in the future.

Answer 2

Pat Breen 0

I encounter this shockingly often. While it's a convenient excuse to ignore emails, it really is a mind boggling issue for a flagship product.

Stefan Blom 357.1K Reputation points MVP Volunteer Moderator

2026-10-23T08:48:39.8533333+00:00

@Pat Breen

You have posted to an old thread from December 2025. Please start your own thread for your question. Use the Ask a question option which you will find at the top of the Q&A page (sometimes, you have to click the menu icon and then click Ask a question).

Good luck.

The current thread will be closed.