Microsoft 365 Copilot App (m365copilot.exe) v19.2604 Crashes Linked to ucrtbase.dll

We have identified an increased rate of crashes affecting m365copilot.exe, specifically version 19.2604. The crash pattern began emerging at the end of April and is now visible across a steadily growing number of organizations, consistently faulting in ucrtbase.dll.

The crash has been observed across more than 600 organizations and is classified as medium severity.

The impact depends on how heavily end users rely on Microsoft 365 Copilot features. Affected environments may experience loss of Copilot Hub functionality, degraded access to cross-app Copilot experiences, or interruptions in AI-assisted workflows across Microsoft 365.

The crash pattern appears strongly associated with the recently released version 19.2604. At this time, there is no documented root cause or validated resolution available.

Organizations should monitor crash trends related to m365copilot.exe, identify endpoints running version 19.2604, and watch for future Microsoft updates or release guidance that addresses Copilot app stability.

The timing and concentration of the crash pattern suggest the issue may stem from changes introduced in recent releases. As Copilot adoption increases across organizations, stability issues in this component may become more visible and operationally relevant.

ControlUp will continue monitoring this crash signature globally and update this finding as additional guidance or remediation becomes available.