Ditto on this, I have a save game with some units that this happens to ie sions, spys, and demons.  Their mana is very erratic. Often I have a bunch of mana at the end of the battle and non when I start the next one.

Sometimes the spy (who doesn't even have any spells to cast in v1.08) will have odd amounts of mana as well. I do have several +50% essence building in my cities. Not sure if that is related.

My save game is saved right before a few battles on my norther border with the "teal" colored faction. If you play through a turn or to and do some tactical battles you will see this behavior it is repeatable. I will post it momentarily.

Weird Mana Save File

Is this common for others? It seems like we are all running into the issue with the bows and ranged attacks, but I'm not hearing much talk about this mana issue. I have tried several games and it always happens...anyone else seeing this?

Hopefully we can get another hotfix for the bows and mana. I consider those two to be fairly serious problems, both added since last patch. I guess that is the double edged sword here. We keep running into issues that really demand a hotfix, but then the hotfix adds new issues. Shame, but I know Stardock will get it fixed eventually. 

In my army i have a dragon, two fire elementals, three imbued champions and sov. 

Only a dragon and one of imbued champions have a mana problem. I also discovered that if i have more than one battle a turn mana zero itself in those two characters in the second battle.

Makes strategic planning quite impossible, very annoying.

Against the trend: i love new bows  

I've seen this as well. I thought it was the auto battle that was making them use up all their spell points, but even after manually doing an easy tactical battle, almost all of them went to 0 mana points. Bad bug.

I'm seeing this a;; the time, though as someone said, not on my sovereign.

In one instance I had two channelers in a defensive combat, one use mana the other didn't. Both at about half mana. After that attle I was immediately attacked again in the same turn and this time both had 0 mana.

tom 

I am also experiencing this bug.  Any caster involved in a battle will have 0 mana after the battle.  Seemed to start happening in my game after I picked up the dragon via the egg quest (many, many hundreds of turns into the game.)  I have tons of Essence temples built, so most of my casters have max mana anywhere from 60 something to near 100.

The first time it happened in this particular game, I had 3 casters in a warband, each with over 60 mana.  They fought a small battle and after the battle (didn't cast any spells), all had 0 mana.  Very, very frustrating.  Since this started happening, neither I nor the AI have any significant mana anymore (every battle drains our casters to 0).  The bug does seem to be affecting the AI, as well.  The AI hasn't cast any spells since this bug appeared in my latest game (first since 1.08).

As others have said, this doesn't seem to be affecting my sovereign, though.  I have not imbued any heroes...all my non-sovereign casters are children or grandchildren.

EDIT:  Nevermind, I see that this bug is known and is fixed in 1.08.037.  I also see that this bug is only fixed in new games and I'll need to uninstall and reinstall the game since I have the older 1.08 beta MP build installed (or wait until tomorrow when a version of 1.08.037 will be released that can install over the top of the 1.08 beta MP build.)

I'm finding some strange mana anomalies after the last update too:

1. Sometimes heroes that have not used any mana, suddenly lose all of it between one battle and the next.

2. Sometimes my heroes stop regenerating mana.  A reload or entering a city fixes this.

With the already desperately low mana-regen, these are some of the most aggravating bugs so far.