OCR-D workflow "Best results for selected pages" fails to detect text regions

[stweil]

The recommended workflow does not recognize any text.
The dewarp step reports that there are no text regions for any page.
So it looks like the previous segmentation step is wrong:

[...]
19:08:24.661 INFO ocrd.task_sequence.run_tasks - Start processing task 'cis-ocropy-dewarp -I OCR-D-SEG -O OCR-D-SEG-LINE-RESEG-DEWARP -p '{"dpi": 0, "range": 4.0, "smoothness": 1.0, "max_neighbour": 0.05}''
Page "FILE_0001_OCR-D-SEG" contains no text regions
Page "FILE_0002_OCR-D-SEG" contains no text regions
Page "FILE_0003_OCR-D-SEG" contains no text regions
Page "FILE_0004_OCR-D-SEG" contains no text regions
Page "FILE_0005_OCR-D-SEG" contains no text regions
Page "FILE_0006_OCR-D-SEG" contains no text regions
[...]

Because of the missing text regions, the final text recognition terminates rather fast without any recognized text.