Strange warning message: None of the data-factories was able to handle this query

[Nicolas.Raoul]

My report (containing many subreports) makes this warning appear:

Deprecated behavior: None of the data-factories was able to handle this query. Returning empty tablemodel instead of failing hard.
WARN - Be aware that the default for this setting will change in version 0.8.11. To avoid this warning, make sure that all data-sources are properly configured and that no report references illegal queries.

I searched on the Internet, it was discussed in a 2009 thread, the conclusion was that it was a bug that has been fixed in August 2009, if I understood well.

I am pretty sure that all of my sub-reports have valid data sources, and indeed my report is generated correctly, including all sub-reports.

Is there something wrong in my report that this warning is telling me about?
If not, can I safely ignore this warning?

Thank you!
Nicolas Raoul

[Taqua]

Your report (or subreport) probably has a value in the "query" attribute that does not match one of the query names defined in any of the datasources. You only get this message if your report actually has some content in the query attribute. If the value there is <null>/empty, we silently skip the data-query step.

In any case I should change that message to make a reference to the correct version number.

[Nicolas.Raoul]

Thanks Taqua, that was the problem!
The sub-reports were OK, but the main report was not (actually I don't use its data source).

Thanks!
Nicolas Raoul