Have you some citizens who are generals.

Dagnabit, was in the middle of uploading my save game to google to post here when forums went boom, and I guess several posts were lost in what I presume was a load-from-backup.

Here's a link to my savegame with this bug in, I think its the prequel 3rd mission, the first one with the Drath:

https://drive.google.com/open?id=0ByxJB3KvvsoJVU1xak9CWTNmamM

The "Cannot Invade. No Genocide Ships." error generates when attempting to invade Dratha (in the northeast part of the map) with my transport a little to the east of Dratha.

This is Crusade, 2.5 (no beta opt-in).

I built it.  The Campaign uses the older troop model where it loads population instead of garrisons (there's no leaders in the campaign), when I launched it, it asked me how many troops and drew from the population of the planets near the shipyard I launched from.

Are you launching from a planet or from a starbase?

Same or similar issue. Base game, latest non-beta version.

Four transports in a fleet. Population 9 in each. Moved them to a starbase to keep them out of the way and safe. About 20-30 turns and at least one save/load game cycle later, when they left the starbase (perhaps) they all had no population showing, which I discovered when I tried to use them to invade a planet.

Going to go test now if they can have any more population loaded back on them from a friendly planet.

Edit: I was able to load population back up again from a friendly planet on the transports which had lost it. It also persisted through a save/load cycle, so bug appears to be starbase related.