ERROR dule.exchangetransactional.TransactionalSyndicator: Failed to activate content.
info.magnolia.cms.exchange.ExchangeException: java.lang.IllegalArgumentException: Illegal character(s) in message header field: mgnl:deleted
	at info.magnolia.module.activation.BaseSyndicatorImpl.activate(BaseSyndicatorImpl.java:448)
	at info.magnolia.module.exchangetransactional.TransactionalSyndicator$2.run(TransactionalSyndicator.java:205)
	at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalArgumentException: Illegal character(s) in message header field: mgnl:deleted
	at sun.net.www.protocol.http.HttpURLConnection.checkMessageHeader(HttpURLConnection.java:489)
	at sun.net.www.protocol.http.HttpURLConnection.isExternalMessageHeaderAllowed(HttpURLConnection.java:459)
	at sun.net.www.protocol.http.HttpURLConnection.setRequestProperty(HttpURLConnection.java:3018)
	at info.magnolia.module.activation.BaseSyndicatorImpl.addActivationHeaders(BaseSyndicatorImpl.java:630)
	at info.magnolia.module.activation.BaseSyndicatorImpl.transportActivatedData(BaseSyndicatorImpl.java:478)
	at info.magnolia.module.activation.BaseSyndicatorImpl.activate(BaseSyndicatorImpl.java:407)
	... 3 more

java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode)