Organisation's sharepoint and onedrive down!

If your organization is experiencing a 503 SERVICE UNAVAILABLE message when trying to access SharePoint Online or OneDrive, it may be due to throttling within the SharePoint service. SharePoint Online implements throttling to maintain optimal performance and reliability, which limits the number of user actions or concurrent calls to prevent overuse of resources.

Additionally, the message you are seeing might indicate that users are being placed in a waiting room due to high demand. This waiting room page has built-in retry mechanisms and does not require users to refresh the page manually, as doing so may delay access further.

To check if there are any temporary service issues affecting your organization, you can refer to the Service Health Dashboard available in the Microsoft 365 admin center.

If the issue persists, it may be beneficial to contact Microsoft technical support for further assistance.

References:

• Unable to access SharePoint Online
• Are users receiving "503" or "Server is busy" or "You are now in line to access this site" error messages?

Hi Valters Kinna

Thank you for reaching out to Microsoft Q&A forum and apologize for the inconvenience

I understand how frustrating and disruptive it can be when critical services like SharePoint and OneDrive go down, especially when it halts your entire organization's workflow. However, to better diagnose and resolve this 503 SERVICE UNAVAILABLE error as quickly as possible, could you provide answers to these key questions?

1. Is your SharePoint deployment on-premises (hosted on your servers), cloud-based (SharePoint Online via Microsoft 365), or hybrid? What version of SharePoint Server are you using (e.g., 2019 or Subscription Edition), and what's the underlying OS?
2. When did the issue start (exact date/time), and have there been any recent updates, password changes for service accounts, or IIS modifications?
3. Can you share relevant excerpts from Event Viewer (Application/System logs) or SharePoint ULS logs around the error time, including any IIS-related events (e.g., event ID 2280) or "Unexpected" entries?
4. Does the error affect all sites/users, or specific ones?
5. What steps have you tried (e.g., restarting IIS app pools, checking server resources like CPU/memory, or testing from different networks/devices)

I am looking forward to hearing from you

Best regards