bpmn20.xml export - signavio core

[colinjay]

I copied and renamed the editor/data/stencilstes/bpmn2.0 stencils in the signavio editor.
I also added some new properties in the "copied" bpmn20.json file.

Problem: If i save  bpmn diagrams, which are created with this "new" bpmn stencil, signavio
only creates an *.signvio.xml file and no *.bpmn20.xml.  file.
Is there any possibility to create bpmn20.xml files for my bpmn20 version?

thx
best regards

[colinjay]

Same happens if i add a new extension (with one new custom connection object) to the core bpmn20 stencilset.

This error occurs:

Something went wrong when trying to save your diagram. Please try again. If the problem resides, please contact the Signavio Support via the envelope symbol in the toolbar.

Tomcat:
java.lang.IllegalStateException: Cannot save BPMN2.0 XML
        at com.signavio.warehouse.model.business.modeltype.BPMN2_0XMLModelType.s
toreRevisionToModelFile(BPMN2_0XMLModelType.java:61)
        at com.signavio.warehouse.model.business.FsModel.createRevision(FsModel.
java:176)