The AbstractAccountChooserValve can throw in an exception like:

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12:20:39,693 ERROR [org.apache.catalina.connector] (http-/127.0.0.1:8080-23) JBWEB001018: An exception or error occurred in the container during the request processing: java.lang.IllegalStateException: JBWEB000043: Cannot create a session after the response has been committed

nal]
ractAccountChooserValve.java:197) [picketlink-jbas7-2.5.3.SP1.jar:2.5.3.SP1]
rValve.java:167) [picketlink-jbas7-2.5.3.SP1.jar:2.5.3.SP1]
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The call "request.getSessionInternal()" needs to be dealt with appropriately.