In architect-html/src/errorHandling/ErrorDialog.tsx:86 the condition errItem.error?.request?.status === 500 || ... === 409 never matches. It is left over from before axios was removed (#4243). The new fetch-based HttpError has no request property, so the generic “Server error occurred…” message is never shown. The same applies to handlePlainText (line 62), which reads response.headers, and HttpError.response doesn’t have that either.
Size S.