If you use Atlassian's Clover and your job specifies a Clover directory (see Enabling the Clover add-on), you will be able to view the Clover coverage summary for the plan.
If your plan contains multiple jobs with Clover, the View latest Clover HTML report link will point to the default job only. In order to see other reports, you must go to the specific job summary, as described in Viewing the Clover code-coverage for a build.