Symptoms

The following message appears in the logs:

Could not load custom field type plugin with key 'com.atlassian.jira.plugin.linker:linker'

They will also notice that any custom fields created before JIRA 4.0 of the type "URL Link Field" will no longer be visible in their JIRA instance.

Cause

Version 1.2 of the JIRA Linker Plugin inadvertently broke backwards compatibility with previous versions of the plugin. The plugin key was altered, which effectively rendered the existing custom field definitions unrecognisable by the new plugin.

Resolution