Who wants to guess what is the cause of this error with the below markup:

 

<ExtendedAdvancedDataGrid ...

dataProvider="{getHosts_pagedResult.lastResult}" ...

           columns:SelectAllAdvancedCheckBoxHeaderColumn width="15"

           ... (more columns here)

</ExtendedDataGrid>

If you figured it out, kudos for being able to read the compilers mind :-)

The issue is the missing declaration of the columns tag.

<grids:ExtendedAdvancedDataGrid ...

dataProvider="{getHosts_pagedResult.lastResult}" ... >

<grids:columns>

            <columns:SelectAllAdvancedCheckBoxHeaderColumn width="15"/>

           ... (more columns here)

</grids:columns>

</grids:ExtendedAdvancedDataGrid>

 If only the compiler spoke the same language as we do :-)