Source view is missing

[mbed67]

The tag @filesource should add a link to the given file’s source next to the name of the file in the top. If you click on it, you would see the highlighted source code. This link is missing. The only thing that is visible is a label that isn't clickable:

An example can be found in phpDocumentor\Tests\ReferenceImplementation.php

Also, the --sourcecode runtime option would create this link to the filesource for every file. This doesn't happen either.