💡 Our Technical Review in summary
Summary
- Microsoft is officially removing legacy ASP.NET DISCO and WSDL web pages from SharePoint Online.
- These endpoints were originally designed in the early 2000s to facilitate the creation of proxies for web services, but they have been deprecated since 2013.
- The decommissioning process began in late October 2025 and is scheduled to be fully completed by the end of November 2025.
- This removal is part of a broader effort to retire obsolete, insecure, and underutilized legacy components in favor of modern API standards.
Impact
- Low Service Impact: Microsoft reports that usage of these endpoints is extremely rare, with most endpoints showing zero active usage across the service.
- Development Workflows: Modern SharePoint development practices do not require these pages. However, legacy applications or scripts from the early 2000s that still rely on SOAP-based discovery via DISCO/WSDL will fail to generate or update proxies.
- Tenant Configuration: These endpoints are not tenant-specific and are not associated with individual tenant ownership or unique configurations.
- End-Users: There is no expected impact on standard end-user functionality or the SharePoint user interface.
Action Required
- Internal Audit: Consult with your internal development and DevOps teams to identify any legacy integrations or automated scripts that might still reference these SharePoint DISCO or WSDL endpoints.
- Modernization: If legacy dependencies are found, prioritize migrating those remote operations to Microsoft Graph, which is the current and supported standard for SharePoint Online integrations.
- Testing: If your organization maintains very old custom-coded solutions, monitor them through November 2025 to ensure no unexpected connection failures occur as the rollout reaches completion.
- Reference: For technical details on the transition, review the “Removal of deprecated DISCO & WSDL aspx pages from SharePoint Online” article on the Microsoft 365 Developer Blog.
Microsoft Official Update
Service: N/A
Category: planForChange
Severity: normal
Updated October 20, 2025: Removal of these pages have started in late October 2025 and will be fully completed by end of November 2025.
ASP.NET DISCO and WSDL pages were the web service APIs for customers who wanted to create a proxy for their web services. The retirement of ASP.NET web services was announced in 2013 and should not be used. We encourage customers to move away from consuming these pages and use Microsoft Graph for remote operations where possible.
Please refer to the following information regarding the DISCO and WSDL endpoints
- These endpoints were originally designed for use with development tools from the early 2000s and were never a preferred or widely adopted method for generating proxy classes in SharePoint development.
- These endpoints are not tenant-specific and are not associated with any individual tenant’s configuration or ownership.
- Usage across the SharePoint Online service is extremely rare. In fact, most of these endpoints show zero usage.
- These endpoints were primarily used in legacy development scenarios and are not required for modern SharePoint development practices.
- If your organization has an internal development team, we recommend consulting with them to confirm whether these endpoints are in use. However, it is extremely unlikely that they are being used in any current development workflows.
Learn more: Removal of deprecated DISCO & WSDL aspx pages from SharePoint Online – Microsoft 365 Developer Blog
