I'm playing the Path of Dark for the first time. Fun times. But I've run into two promotion quests that I cannot complete because the items I need to retrieve never populated. The first and most annoying is the Lich promotion. I have to retrieve soul jars from the Walls of Mist in Celeste. Well, I went through the entire thing, got to the end and opened the chest but...no jars. They aren't in there. I tried again, same deal. I even scoured Castle Gloaming, where the same item is hidden when you play the Path of Light, but they weren't there, either.

The second broken quest is an honorary one since I don't have any of that character class in my party, but still. It's to retrieve a dragon egg from the dragon lair in the Land of the Giants. Okay. I went in while invisible to scout. In the front room were a handful of dragons, including the Mega Dragon. I went to sneak past, but there was a green dragon stuck in the hallway and I had to kill is to pass by. Found a chest in the back room, but surprise! No dragon egg. Then I had to fight my way back out, but on top of no egg in the chest, the Mega Dragon had disappeared! And it didn't clip through the wall as occasionally happens, it was just not there at all anymore. Leaving and returning didn't work.

I have no way to complete either of these quests. The Judge does not have the items to give me, as he will only give me items I've already possessed, but dropped. I don't need either of these quests to complete the game, though going through it without Lloyd's Beacon, which I can't use because I can't promote my sorcerer to lich and get Grand Master spells, is annoying. Any ideas?

you're in the wrong dragon cave for the egg there's another one.
as for the jars just spawn them in I guess

Lich Jars: I seem to recall the warlocks inside Thunderfist Mountain might have some lich jars, so try raiding them if you haven't already.

Warlock: There are (at least?) two dragon cave entrances. The egg isn't in the main entrance, guarded by lots of dragons.

Okay, I found the second dragon cave. Somehow in all my play throughs of this game, I never found that cave before. Thanks!

The Lich Jars in Thunderfist Mountain were used to complete a different quest. I think it was one of the four you have to do for the advisors before getting to the final quest. I thought they were for the Lich promotion, but when I went back to that teacher, he wouldn't take them. Wrong quest item, I suppose. On a side note, it's hilarious how they just look like a case of mason jars.

And now I've encountered a new problem. I've completed the final quest, and gotten the Overthruster, but, um...when I couldn't find the Lich Jars, I went kind of apeshit on The Pit and Castle Gloaming and killed everyone in there. Path of Dark, after all. Now Kastore has locked the door to the throne room, and I can't get in to give him the Overthruster and finish the game! Oy. I guess I'll wait until the Pit respawns. I think I'll go on a murder spree in Erathia and land myself in jail for a year. That should do it.

The games do have a fix for lost quest items. I discovered this in M&M6 when I discarded the item required for the Priest promotion quest.

Go to the Arbiter in Harmondale and initiate the dialog "I lost it..." It then provides the missing quest item or states that you never had it.

Maybe the OP should try that and see what happens.

The error I'm talking about isn't related to the player dropping the quest item, it is how the quest item doesn't spawn in the chest in the first place because the chest is too full.

The OP indicated he already tried the MM7 version of the Arbiter with no luck.

Yes, I tried getting the Lich Jars from the Arbiter, and he didn't have them. That trick only works when you drop a quest item you've already found. I think Bookwyrm's idea is what must have happened. That chest in Celeste was rather full, and the Lich Jars are a big item. I'm in the process of trying to get myself tossed in jail for a year to give the maps time to reset, but no one seems to want to arrest level 75 characters, no matter how many towns I depopulate. Might have to do it the old fashioned way.

It's probably too late for a player who doesn't want to start over, but doesn't Greyface's patch fix the Lich Jars bug?

Well, in case anyone is curious, I was able to pass the time by walking back and forth between two maps, passing five days at a time until The Pit reset. Then I was able to report to Kastore and finish the game. I then tried to go back to Celeste and redo the Lich Jars quest, but Celeste hadn't reset yet. Considering I depopulated that place before I turned on The Pit, I'm a bit disappointed. I'll try taking a few more long walks and hope it resets again soon so I can make another attempt at those jars.

I'd love to hear if a Celeste reset also gets the Walls of Mist to repopulate the jars for you.

I have no idea how the area resets work for the Breeding Grounds and Walls of Mist since those are special dungeons that reset monsters each time you enter.