I've changed the dynamic task list model to not persist the internal java.util.Collections implementation of a synchronized list. This list is marked as transient and is constructed as necessary on creation and deserialization.

When conversion exceptions are thrown we now attempt to convert the task to the new model via a quick SAX converter. When this process is finished a new task list is returned. When lists are saved, they will be persisted in the new, much simpler task list model which will deserialize cleanly without any conversion necessary.

Updating the title of this issue to reflect the fact that this will happen when JDK versions are changed and not just an upgrade to 1.5

Ted / Peter

I thought I had the same problem with a broader context, as I was running a brand new install of Confluence 2.3.3. However, it turned out I was using JDK (1.)6, which is distinctly unsupported by the Atlassian product range (look slike that's the problem with yours Ted). It works fine for us using JDK (1.)5.

Hope this helps for now, although Atlassian should really start addressing the JDK 6 compatibility issues, now that it's out and many are moving towards it for developing new plugins.

Kind Regards
Jag

An additional note on this. The context is much broader than the upgrade scenario. Our Confluence install was completely new and we experienced this issue.

Any update or workaround for this? I'm having the same problem.

Any update on this issue? We're in the same boat as everyone else...

I also get this error after a JDK upgrade for completely new task lists, such as {dynamictasklist:neverusedthisnamebefore}

Build Information:
confluence.home: /var/lib/jboss/data/confluence
system.uptime: 14 hours, 3 minutes, 16 seconds
system.version: 2.3
build.number: 641

Server Information:
Application Server: Apache Tomcat/5.5.20
Servlet Version: 2.4
Database Dialect: net.sf.hibernate.dialect.PostgreSQLDialect
Database Driver Name: N/A
Database Driver Version: N/A

Memory Information:
total.memory: 285 MB
free.memory: 98 MB
used.memory: 187 MB

System Information:
system.date: Thursday, 11 Jan 2007
system.time: 10:54:55
system.favourite.colour: Claret
java.version: 1.6.0
java.vendor: Sun Microsystems Inc.
jvm.version: 1.0
jvm.vendor: Sun Microsystems Inc.
jvm.implementation.version: 1.6.0-b105
java.runtime: Java(TM) SE Runtime Environment
java.vm: Java HotSpot(TM) Server VM
user.name.word: jboss
user.timezone: Europe/Paris
operating.system: Linux 2.6.17.8-server.piv
os.architecture: i386
fs.encoding: ISO-8859-1

We use Confluence Enterprise 2.1.5a (unlimited user edition).This issue is preventing our upgrade to (version 2.2.9).
It is impossible to manually find out and migrate hundreds of tasklists on different pages.

Please increase the priority.

The above workaround we guess is not feasible to our setup since we have a large amounts of pages which have dynamic task list been used .

We are not able to use the older version of the JDK (1.4) as its' killing the confluence instance due to conflict with other plug-in/macro dependencies.

we are looking another workaround where in we can migrate the older XML to newer versions. This is a roadblock to our production upgrade.

While this JDK problem awaits developer resources, the workaround is to manually transfer dynamictasklist content as described at

http://confluence.atlassian.com/display/DOC/Dynamic+tasklist+macro+edits+fail+with+ConversionException+after+JDK+upgrade

Cheers,
David S