E01031 — retired

The Bird API no longer returns E01031. If you reached this page from an older stored or logged response, that reference is still valid: error codes are never renamed or reused, so E01031 still identifies the failure your record captured.

If your integration still handles E01031, you can safely remove that handling: the API no longer produces it. A request that once failed this way either succeeds now or reports a different code, and the response tells you which.