GeoModelXml problem: creating the materials by using 'materialref' tag .

Hi expert,

I'm using the GeoModelXml to build the HGTD geometry but when I tried to construct a material base on others materials by using <materialref/> tag.

Here an example.

<material name="CuKapton" density="2.94">
    <materialref fraction="0.3858" ref="Kapton"/>
    <materialref fraction="0.6142" ref="Copper_Ma"/>  
</material>

When I was running gmex, it shows me the error message:

 MEX!!!VP1MESSAGE: VP1QtApplication:
 std::exception:

VP1QtApplication:
 Error 'evaluate: empty or white space expression. Last good expression was 2.94' sending event '11QTimerEvent' to object '' ('6QTimer')

throwing
 the exception again...

terminate
 called after throwing an instance of 'std::exception'

  what(): 
 std::exception

Aborted
 (core dumped)

Many thanks for any help.

@cohm @dshope @aleopold

Best,

Selaiman