I use the current version of KNIME with all free extensions. And I don't have a "report" icon on the top menu bar. I'm using my workspace with about 30-40 groups inside. This was tested also on the fresh KNIME install fetched today (KNIME + all free extensions).
Still no solution, but I found a workaround. I had to split my workspace content into two separate workspaces (by moving appropriate directories). And now reporting works for the one of them (and for the second one - still doesn't).
The conclusion is that the problem is caused by the content of the workspace (one or several workflows). Unfortunatelly, now I don't have time to investigate which workwlow is the culprit of this situation.