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Microsoft Mission Critical Blog
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Legacy SharePoint Authentication (IDCRL) Is Retiring — What to Do Before May 1, 2026

mikeleemsft's avatar
mikeleemsft
Icon for Microsoft rankMicrosoft
Mar 03, 2026

This post explains what’s changing, how to detect legacy sign-ins, and the practical steps to move to modern authentication (OAuth) before the cutoff dates.

Audience: SharePoint admins, M365 admins, and anyone running automations that access SharePoint Online/OneDrive. This post explains what’s changing, how to detect legacy sign-ins, and the practical s...
Published Mar 03, 2026
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mw365
MikeYam's avatar
MikeYam
Copper Contributor
Apr 08, 2026

Same issues here. We have multiple scripts and applications stopped working since 2 April.
In our Purview Audit Log, the latest activity of IDCRLSuccessSignIn was on 2 April.