java.lang.IllegalArgumentException: Illegal pattern character 'u'
at java.text.SimpleDateFormat.compile(SimpleDateFormat.java:768)
at java.text.SimpleDateFormat.initialize(SimpleDateFormat.java:575)
at java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:500)
at java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:475)
at net.sourceforge.plantuml.graphic.DateEventUtils.addEvent(DateEventUtils.java:60)
at net.sourceforge.plantuml.graphic.GraphicStrings.getTextBlock(GraphicStrings.java:130)
at net.sourceforge.plantuml.graphic.GraphicStrings.calculateDimension(GraphicStrings.java:152)
at net.sourceforge.plantuml.graphic.GraphicStrings.drawU(GraphicStrings.java:135)
at net.sourceforge.plantuml.ugraphic.ImageBuilder.getFinalDimension(ImageBuilder.java:159)
at net.sourceforge.plantuml.ugraphic.ImageBuilder.writeImageInternal(ImageBuilder.java:128)
at net.sourceforge.plantuml.ugraphic.ImageBuilder.writeImageTOBEMOVED(ImageBuilder.java:123)
at net.sourceforge.plantuml.PSystemError.exportDiagram(PSystemError.java:118)
at net.sourceforge.plantuml.SourceStringReader.generateImage(SourceStringReader.java:113)