Having invaded 2 more planets the tooltip now says "Missing Info (3)  +3", so I'm sure that it's the Eager ideology trait.

Yep I noticed that also in my game, just always forget to say something about it on the boards.  It is indeed from the malevolent ideology trait that gives you a permanent boost to morale for every planet you invade.

This trait also makes it so that malevolent civs never really have to worry about the Large Empire Penalty to morale.  You get +1 to morale for every planet you conquer, and the LEP is only -.2 for every planet you own.  The longer you go conquering, the less need you have for wasting space on morale boosters for your planets.  Makes it pretty easy to keep morale on your planets capped at 100%; which seems kinda ironic that it is easier to keep the populace happy as "evil" than it is as "good".  Neener neener to all the "goody goody" civs

Thanks for the feedback.

Are you are continuing an old save game from 1.0?  I believe there was fix for this, but you'll only see the fix in a new game. 

No, this is a brand new game started on 1.31.

Actually, to be precise, it was the Snathi scenario.

Yes a ticket would be helpful.  I am suspecting the problem is in one of the improvements  

ticket: https://esupport.stardock.com/index.php?/Tickets/Submit

Thanks!

Ok thanks we're looking at it

This is still happening in 1.41.  Same situation, brand new game on 1.41, got the malevolent ideology perk "Eager" and after successful invasion of an enemy planet "Missing Info" shows up as +1 on the approval tooltip.

This is still happening in 1.7, as reported in the original post and in the ticket I opened.  Brand new game on 1.7  Snathi scenario, again, although I suspect it's happening for all malevolent civs that take the Eager trait.

While I agree that it is more important that the trait work than that the tooltip is correct, it is now 10 and a half months since the problem was reported.  One might think that a "few lines of code" could have been written in that time.