The security validation for this page is invalid and might be corrupted. Please use your web browser's Back button to try your operation again
What causes it and how to fix it:
- X-RequestDigest expires ~30 min after page load — but adding it by hand in SPFx makes things worseWrites 403 "security validation is invalid" on a long-open page; raw fetch needs a fresh digest from /_api/contextinfo, but in SPFx a hand-set header switches SPHttpClient's own digest and 403-recovery OFFCause and fix →