Simplified DocBook RelaxNG schema not valid?

[Frank Arensmeier <farensmeier@gmail.com>]

Hi there!

For a project I am working on, I did a couple of tests with the Simplified DocBook schema. The definition I downloaded was 5.1CR3. When I open that schema in Oxygen I see a couple of validation errors:

System ID: /Users/brillo/Downloads/sdocbook.rng
Description: multiple definitions of start without "combine" attribute
Start location: 290:11

System ID: /Users/brillo/Downloads/sdocbook.rng
Description: multiple definitions of start without "combine" attribute
Start location: 2390:11

System ID: /Users/brillo/Downloads/sdocbook.rng
Description: multiple definitions of start without "combine" attribute
Start location: 6644:11

System ID: /Users/brillo/Downloads/sdocbook.rng
Description: multiple definitions of "db.admonition.blocks" without "combine" attribute
Start location: 6736:40

System ID: /Users/brillo/Downloads/sdocbook.rng
Description: multiple definitions of "db.os.inlines" without "combine" attribute
Start location: 6826:33

System ID: /Users/brillo/Downloads/sdocbook.rng
Description: multiple definitions of "db.programming.inlines" without "combine" attribute
Start location: 6835:42

System ID: /Users/brillo/Downloads/sdocbook.rng
Description: multiple definitions of "db.markup.inlines" without "combine" attribute
Start location: 6853:37

Most of these errors seem to be caused by the fact that there are some duplicates of element definitions. Removing those duplicates however does not make Oxygen happy. Instead, it says: found element matching the prohibited path start//empty in the simplified XML form of the schema[…].

What is going on here? Can this be fixed? Shall I file a bug report somewhere? Do pigs fly?
Thanks!

/frank

Frank Arensmeier
farensmeier@gmail.com