The FlumeConfiguration value should have a reasonable default in the case that configuration files do not have any value. As an example, 0.9.3 config files do not have the flume.master.webapp.root values and if used after an upgrade to 0.9.4, flume's status webpages will fail.
(Jira READ-ONLY currently, will assign proper JIRA ID when available).
Edited flume-distribution/target/flume-distribution-0.9.5-SNAPSHOT-bin/flume-0.9.5-SNAPSHOT/conf/flume-conf.xml to remove webapps properties.
Started master and node from flume-distribution/target/flume-distribution-0.9.5-SNAPSHOT-bin/flume-0.9.5-SNAPSHOT