A guest user authentication issue blocked external collaboration for weeks. Teclara used Claude Code and Lokka MCP to diagnose it in 20 minutes.
A growing technology company in Ontario had dozens of external collaborators locked out of SharePoint and Teams for weeks. Azure AD recognized every guest user. SharePoint did not. The client's IT team had exhausted their troubleshooting ideas, and project timelines with external partners were starting to slip. Teclara diagnosed the root cause in 20 minutes using Claude Code and the Lokka MCP server, then fixed it with a single PowerShell command. This is how that played out. The Client A mid-sized technology company with approximately 85 employees, based in Ontario. They collaborate heavily with external consultants, contractors, and partner organizations, which means guest user access in Microsoft 365 is a daily operational requirement. SharePoint handles their document storage and Teams runs their collaboration, so both platforms depend on guest users being able to log in and work alongside internal staff. The Challenge Guest users were being invited through Azure Active Directory and successfully accepting those invitations. Azure AD recognized them and the provisioning process was working correctly. The problem showed up one step later: when those same guest users tried to access SharePoint sites or Teams channels, authentication would fail or hang indefinitely. Internal employees had no issues accessing the same resources. The disconnect was entirely limited to external collaborators, and it had been going on for several weeks before the client reached out to Teclara. External consultants could not review or contribute to project documents. Partner organizations were locked out of collaborative workspaces. Project timelines were slipping, and the client's reputation with external stakeholders was starting to take damage. Their internal IT team had run through basic troubleshooting without isolating the root cause. The Diagnostic Teclara's team connected Claude Code to the client's Microsoft 365 tenant using Lokka, an open-source MCP (Model Context Protocol) server for Microsoft Graph. Lokka