As we figured out in #1969870: REST export view should default to JSON the user don't expect to see a more or less unhelpful exception.
The idea of that issue was to fallback to a certain format (json).
This issue provides an alternative: Throw a message which explains the user to either send a header or use the views preview.
| Attachment | Size | Status | Test result | Operations |
|---|---|---|---|---|
| error.png | 27.81 KB | Ignored | None | None |