A user reports..

We are using the custom field plugin example "Last commented user" as described in you tutorial about custom field types. Our problem is, that if we try to sort in the issue list of a project after these "Last commented user" we get the following error:

Issue Navigator

1. Errors: An error occurred searching: java.lang.AbstractMethodError: com.atlassian.jira.plugin.customfield.example.LastUserCommentedCFType.compare(Ljava/lang/Object;Ljava/lang/Object;Lcom/atlassian/jira/issue/fields/CustomField;)I
2. An error occurred searching: java.lang.AbstractMethodError: com.atlassian.jira.plugin.customfield.example.LastUserCommentedCFType.compare(Ljava/lang/Object;Ljava/lang/Object;Lcom/atlassian/jira/issue/fields/CustomField;)I

The Issue Navigator allows you to browse all the issues in the system. Filters allow you to limit the issues that you see.

Using the panel on the left, you can create and edit new filters.
ERRORS:

• An error occurred searching: java.lang.AbstractMethodError: com.atlassian.jira.plugin.customfield.example.LastUserCommentedCFType.compare(Ljava/lang/Object;Ljava/lang/Object;Lcom/atlassian/jira/issue/fields/CustomField;)I

• An error occurred searching: java.lang.AbstractMethodError: com.atlassian.jira.plugin.customfield.example.LastUserCommentedCFType.compare(Ljava/lang/Object;Ljava/lang/Object;Lcom/atlassian/jira/issue/fields/CustomField