Fixed, thanks!

Thanks for fixing this, Derek!

I did notice this line in the notes for 1.5: ''Familiars will not get bonus levels if their summoner get bonus levels on his summons''

As far as I know, those Summons never had extra levels? At least not in my last 1.4 game. Or did you change that after reading this post, and removed it again directly afterwards?

While bonus levels might be cool, they could be OP. With your fix, the Familiar is not exactly useless, but still underwhelming. A speed of 3, preferably 4 or 5, would give it some actual use.

The only use I've ever found for a Familiar is to sit in my capital giving me twice as many Freezes/ Withers etc. It can be quite handy if the only hero you currently have with useful strategic spells is your sovereign; you get to cast those spells twice as often, you don't have to worry about the cooldown so much.

Derek, as of 1.5 this bug is back.

Even worse, Familiars cannot summon anything anymore.

Please fix both bugs!

Are you continuing from an old save? If not you might need to Verify Integrity of Game Cache in steam and / or delete your folder in My Documents. 

I tested this and I can summon all monsters (that are available to Ceresa) in and out of combat with the exception of the crag spawn and air elemental using the familiar. Also, make sure you haven't already summoned a creature of the type you are trying to summon in combat. Each summoner is limited to 1 summoned unit of each type for most of the summons. I think skeletons are the exception. 

It's a bug. The familier can summon the Air Elemental in combat, however. This most likely is an XML issue. I'm just not at my home PC to confirm that.