This is also the case if I search for references, organize imports or click on a method name in a stacktrace.
Error Details:

eclipse.buildId=unknown
java.version=1.6.0_13
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=de_DE
Command-line arguments: -os win32 -ws win32 -arch x86


Error
Thu Mar 03 08:50:54 CET 2011
An internal error occurred during: "Searching...".

java.lang.IllegalArgumentException: Class file name must end with .class
at org.eclipse.jdt.internal.core.PackageFragment.getClassFile(PackageFragment.java:182)
at org.eclipse.jdt.internal.core.util.HandleFactory.createOpenable(HandleFactory.java:109)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1174)
at org.eclipse.jdt.internal.core.search.JavaSearchParticipant.locateMatches(JavaSearchParticipant.java:94)
at org.eclipse.jdt.internal.core.search.BasicSearchEngine.findMatches(BasicSearchEngine.java:223)
at org.eclipse.jdt.internal.core.search.BasicSearchEngine.search(BasicSearchEngine.java:507)
at org.eclipse.jdt.core.search.SearchEngine.search(SearchEngine.java:551)
at org.eclipse.jdt.internal.debug.ui.actions.OpenTypeAction.findTypes(OpenTypeAction.java:164)
at org.eclipse.jdt.internal.debug.ui.actions.OpenTypeAction.findTypeInWorkspace(OpenTypeAction.java:143)
at org.eclipse.jdt.internal.debug.ui.console.JavaStackTraceHyperlink$1.run(JavaStackTraceHyperlink.java:106)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

simon.erhardt,

1) Can you please share your installation details with us from MyEclipse > Installation Summary > Installation Details? Please paste them here for me.

2) Did you update/install any plugins lately ?

I would recommend you a quick fix using pulse. Please do the following -

a. Open Pulse. (Start > Programs > Pulse > Pulse Explorer or download the same from www.poweredbypulse.com)
b. Start Pulse
c. Select appropriate Eclipse realm from the dropdown list. If you are on ME 8.6, select Eclipse Galileo; in case you are on 9.0, select Eclipse - Helios
d. From My Profiles, Select your MyEclipse profile
e. Right click on the same and click on re-install and run
f. This will open a wizard which will guide you through the rest of the steps

3) Start the IDE with -clean as command args. Here is how it can be done :
http://myeclipseide.com/PNphpBB2-viewtopic-t-10280.html.

Let me know how this works for you.

Hello Swapna,

1) see below
2) I checked the MyEclipse Configuration Center, it shows no updates that are available
Quick fix: I don't like to reinstall MyEclipse until you say that it's absolutely neccessary to fix this issue.
3) I will try that, but since the error occures after an unpredictable time it is hard to say immediately if it helped. I will give you a response to that later.

*** Date:
Donnerstag, 3. März 2011 11:14 Uhr MEZ

** System properties:
OS=WindowsVista
OS version=6.1.0
Java version=1.6.0_13


*** MyEclipse details:
MyEclipse Blue Edition
Version: 8.6.1 Blue
Build id: 8.6.1-Blue-20101117


*** Eclipse details:
MyEclipse Blue Edition

Version: 8.6.1 Blue
Build id: 8.6.1-Blue-20101117






Eclipse startup command=-os
win32
-ws
win32
-arch
x86
-showsplash
-launcher
C:\Dev\MyEclipse-Blue-Edition-8.6\myeclipse-blue.exe
-name
Myeclipse-blue
--launcher.library
C:\Dev\MyEclipse-Blue-Edition-8.6\../Genuitec/Common/plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.0.200.v20090519\eclipse_1206.dll
-startup
C:\Dev\MyEclipse-Blue-Edition-8.6\../Genuitec/Common/plugins/org.eclipse.equinox.launcher_1.0.201.R35x_v20090715.jar
-install
C:/Dev/MyEclipse-Blue-Edition-8.6
-configuration
configuration
-vm
C:/Dev/Genuitec/Common/binary/com.sun.java.jdk.win32.x86_1.6.0.013/jre/bin/client/jvm.dll

Hello again,

no, starting with -clean command line argument does not solve the problem.

Simon Erhardt

simon.erhardt,

Have a look at these threads and check if any of the suggestions discussed works for you.

http://www.myeclipseide.com/PNphpBB2-viewtopic-t-20067.html
http://stackoverflow.com/questions/6816/eclipse-class-file-name-must-end-with-class-exception-in-java-search
http://www.eclipse.org/forums/index.php?t=tree&goto=262226&

Let us know how it helps you.

Closing and reopening solved my problem. Thanks!

simon.erhardt,

Glad that it is working.
Do let us know if you have any issues.