After updating the mars plugin version 1.2.2 I opened a workflow in the new BPMN2 Diagram Editor moved one of the diagram nodes a bit and saved the changes. This particular diagram was lasted editor using exporterVersion="126.96.36.199511241736" and it worked fine. The new diagram editor is exporterVersion="188.8.131.52512032052".
When I load this diagram (after editing) in my execution environment I get an hundreds of warning when loading up the workflow in my execution environment (I have shown an example of one of them below). Apart from the fact that it clutters the log file, it also takes much longer to load.
*** Example of error ***
08:04:13.200 [main] WARN o.d.core.xml.ExtensibleXmlParser - (null: 1,549, 100): schema_reference.4: Failed to read schema document 'http[nolink]://www.omg.org/spec/BPMN/20100524/DI-XMI', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.