Error message on startup

[simon.eu@…]

What steps will reproduce the problem?

1. Cannot provide any more details, sorry – just receive an error message when starting josm.

What is the expected result?

What happens instead?

Please provide any additional information below. Attach a screenshot if
possible.

Build-Date: 2011-06-05 09:17:56
Revision: 4115
Is-Local-Build: true

Identification: JOSM/1.5 (4115 SVN de)
Memory Usage: 30 MB / 1777 MB (22 MB allocated, but free)
Java version: 1.6.0_25, Sun Microsystems Inc., Java HotSpot(TM) 64-Bit Server VM
Operating system: Linux

Plugin: editgpx
Plugin: measurement

java.lang.IncompatibleClassChangeError: Expecting non-static method org.openstreetmap.josm.actions.UpdateDataAction.getEditLayer()Lorg/openstreetmap/josm/gui/layer/OsmDataLayer;
	at org.openstreetmap.josm.actions.UpdateDataAction.updateEnabledState(UpdateDataAction.java:40)
	at org.openstreetmap.josm.actions.JosmAction.initEnabledState(JosmAction.java:160)
	at org.openstreetmap.josm.actions.JosmAction.installAdapters(JosmAction.java:149)
	at org.openstreetmap.josm.actions.JosmAction.<init>(JosmAction.java:93)
	at org.openstreetmap.josm.actions.JosmAction.<init>(JosmAction.java:68)
	at org.openstreetmap.josm.actions.UpdateDataAction.<init>(UpdateDataAction.java:23)
	at org.openstreetmap.josm.gui.MainMenu.<init>(MainMenu.java:116)
	at org.openstreetmap.josm.Main.<init>(Main.java:226)
	at org.openstreetmap.josm.gui.MainApplication.<init>(MainApplication.java:59)
	at org.openstreetmap.josm.gui.MainApplication.main(MainApplication.java:231

[anonymous]

Edit: I deleted the josm directory, checked it out again from SVN, and re-built it. Now it works.
Is it possible that sometimes kind of a «make clean» is necessary?

[stoecker]

Sometimes "ant clean" is necessary.