Mirth version 3.0.1 Error transforming XML

We have a couple of channels created in 3.0.1, both where the data type has been set as XML, the first one reading from a database and passing a JSON object to the second channel that does some further database queries and writes another JSON object to a number of file locations.



Initially all works well. However after making any kind of change, even just changing the name of the file to be read to, we receive the following error when processing data in the second channel:



DefaultXMLSerializer error

ERROR MESSAGE: Error transforming XML

java.lang.NullPointerException

at com.mirth.connect.plugins.datatypes.xml.DefaultXML Serializer.toXML(DefaultXMLSerializer.java:54)....

....



This error is not replicated when creating and running the same channels in version 3.0.3.



I have noticed that after making any change, the Inbound and Outbound Properties area of the Set Data Types dialog box show as "This data type has no properties".



Is there a bug in 3.0.1, or is there something that I have missed?



Thanks in anticipation...

Mirth version 3.0.1 Error transforming XML