Error when using Export to XML

Hi guys 'n gals,

I have a fairly simple microflow, which uses a Export to XML activity to create an XML from a domain. However, suddenly, I keep running into the error below:

com.mendix.systemwideinterfaces.MendixRuntimeException: com.mendix.core.CoreException: com.mendix.modules.microflowengine.MicroflowException: No meta factory found for feature 'default'; this usually means that axiom-impl.jar is not in the classpath
	at Storingsinfo.RH_GetXML (Export with mapping : 'Export to XML')

It has worked before, and I haven't changed any notable things.

Any tips are highly appreciated