Plantuml rel. 8027 does not compile under OpenJDK, as present in current Fedora Rawhide (java-1.8.0-openjdk-1.8.0.60-5.b16.fc23).
$ javadoc -d javadoc -sourcepath src net.sourceforge.plantuml
...
Generating javadoc/net/sourceforge/plantuml/AnimatedGifEncoder.html...
src/net/sourceforge/plantuml/AnimatedGifEncoder.java:139: error: invalid use of @return
* @return
^
src/net/sourceforge/plantuml/AnimatedGifEncoder.java:261: error: invalid use of @return
* @return
^
'@return' in void methods seems to be error now, it was just a waring in java-1.8.0-openjdk-1.8.0.45.