[German]Users of Microsoft Outlook Classic have been plagued by high CPU load peaks (e.g. when typing texts) for months. After Microsoft acknowledged this problem with Office 365 (from version 2406, build 17726.20126), there is now also a schedule for a bug fix.
High CPU load when typing in Outlook 365
Microsoft confirmed a problem with the classic version of Outlook 365 in the support article CPU spikes when typing in classic Outlook for Windows on April 14, 2025. It states that when typing a simple email in the classic version of Outlook for Windows, the CPU load may increase by 30 to 50% at certain times and increase power consumption. Users can observe this effect by opening the Task Manager in parallel and observing the CPU load when typing.
According to Microsoft, this problem can occur after updating to version 2406 build 17726.20126 and higher in the Current Channel, Monthly Enterprise Channel or the Insider Channels. I had addressed this in the blog post Outlook 365: Microsoft confirms CPU spikes while typing and mentioned that Microsoft is investigating the error.
Microsoft presents a schedule for the fix
Now Microsoft has probably found a cause and updated the support article CPU spikes when typing in classic Outlook for Windows to April 24, 2025 (noticed here). It states that the Word team has implemented a fix that will soon be available in the following channels:
- Beta channel (version 2505 build 18822.15000) – Expected release in early May 2025, see Update History for Office Beta Channel – Office release notes.
- Current Channel Preview (version 2505 18827.20000) – Expected release mid-May 2025, see Update History for Office Current Channel (Preview) – Office release notes.
- Current Channel (Version 2505 18827.20000) – Expected release end of May 2025 , see Update history for Microsoft 365 Apps (listed by date) – Office release notes.
The developers have also discovered that the problem is now also occurring in the Semi Annual Channel. Anyone who urgently needs to solve the problem there has the option of resetting Office 365 to version 2405. According to Microsoft, this is not recommended as there have been security updates since this version. If required, further information can be found in the linked support article, including how to revert to version 2405.
