How were you not able to place spies? Did you get a dialog box telling you so, or after selecting a spy o place was it unresponsive when clicking on the planet?
I can bring up the planet screen either by:
(1) selecting the planet and then clicking SPY, or
(2) from the Espionage window select place agent and then select a planet
but then the Place Agent button is greyed out so I can only click DONE.
I tried researching Xeno Comm. and Universal Translator but that had no effect.