I'm getting an error when opening Outlook on the web that says "Something went wrong" and "Refresh the application." The details show a BootResult failure, a CryptographicException during StartupData, and an HTTP 500 X-OWA-Error from the Outlook web application. Is this likely part of the Microsoft 365/Exchange Online service issue, or should I start with clearing my browser cache?
3 Answers
Yes, this looks very likely to be connected to the broader Exchange Online and authentication problems. A server-side HTTP 500 error usually isn’t fixed by clearing your local cache, so I’d check the service health dashboard and wait for Microsoft to resolve it.
The webmail service has been working for some users, while the desktop Outlook client is failing for others, so the impact may be inconsistent across accounts. For affected desktop clients, rebuilding the Outlook profile or removing the local OST file and letting it recreate can help, but back up or verify anything important first.
There have also been reports of problems in the Microsoft 365 administration portal and Exchange Online, which makes a broader service incident more likely. Opening a support ticket is still worthwhile, especially if the outage continues, but this error doesn’t primarily look like a cache problem.
We saw the same split in our office, with only about half the users affected. Since the issue appeared unevenly, we decided to wait for the service-side fix rather than rebuild every profile immediately.