I get this error when trying to add a task to a task list.

Cause:
com.thoughtworks.xstream.converters.ConversionException: Cannot construct java.util.Collections$SynchronizedRandomAccessList: java.util.Collections$SynchronizedRandomAccessList ---- Debugging information ---- required-type : java.util.Collections$SynchronizedRandomAccessList cause-message : Cannot construct java.util.Collections$SynchronizedRandomAccessList: java.util.Collections$SynchronizedRandomAccessList class : com.atlassian.confluence.extra.dynamictasklist.model.TaskList message : Cannot construct java.util.Collections$SynchronizedRandomAccessList: java.util.Collections$SynchronizedRandomAccessList line number : 3 path : /com.atlassian.confluence.extra.dynamictasklist.model.TaskList/tasks cause-exception : com.thoughtworks.xstream.converters.reflection.ObjectAccessException -------------------------------

com.thoughtworks.xstream.converters.ConversionException: Cannot construct java.util.Collections$SynchronizedRandomAccessList: java.util.Collections$SynchronizedRandomAccessList
---- Debugging information ----
required-type : java.util.Collections$SynchronizedRandomAccessList
cause-message : Cannot construct java.util.Collections$SynchronizedRandomAccessList: java.util.Collections$SynchronizedRandomAccessList
class : com.atlassian.confluence.extra.dynamictasklist.model.TaskList
message : Cannot construct java.util.Collections$SynchronizedRandomAccessList: java.util.Collections$SynchronizedRandomAccessList
line number : 3
path : /com.atlassian.confluence.extra.dynamictasklist.model.TaskList/tasks
cause-exception : com.thoughtworks.xstream.converters.reflection.ObjectAccessException