@고기육수
Also there are some other important things you must know:

Some bugs might not be caused by your mod, but still occurs in your mod's dungeon. This is because there are four types of overflow in this game. I have wrote a guide for details, see:

Mod Limit CTD : Four Types of Overflow
https://steamcommunity.com/sharedfiles/filedetails/?id=2218956201

This information should be well known on DD discord now, but still many players and modder isn't aware of it. When met these CTDs, the bug is NOT caused by mod, but by the limit of game itself. Since your mod contains too many new monsters and pictures, it's easy to cause the overflow of memory allocation.

Don't be discouraged, your mod has NO error except for the summon mash, I can swear for it.

The following are my discussion with "davidb11" that been moved here.

Please make it clear that I mean no offence and just want to tell you the true reason of the crashes in your old version. There is no regret in your great work, even for the old one.

@davidb11
There are much more things than you know.

First, what I am talking about, is not the current version that you are playing. I am talking about the old version of this mod that can spawns many individual quests in town area. The creator 고기육수 gave up that old version and delete all the quest spawns because of many players report bugs on the mod.

I, here, must told him why the old version will cause bug, because I had tried to fix bugs in his old version.

In the old version there are many curios in those spawned town area quests. Some of them can summon Shamblers when use laudanum on them. BUT it will crash when you do so. The reason is the missing of this line
named: .name summon_mash_shambler .chance 1 .types shambler_C
in the mash files of town area, thus the game cannot find what to summon when players are in the quests of town area.

Clear?

@davidb11
I just hope him could get to know the true reason of those crashes on old version.

Second.
Besides, there are many shape-shifting monsters (including transformation after death) in this mod. Coding on these monster styles must be very careful, since if you write any "fx" on shape-shifting skills, the game will certainly CRASH when doing transformation.

I find the reason of this kind of crash and have told other modders to help them fix this bug (for example Exaelus' Arduous Edition Mod). So here I want to inform 고기육수 too, just in case.

@davidb11
This IS the same workshop project of both the new and the old with the same workshop ID as 1472935369. There is NO old version, this is the old one before 고기육수 been forced to update it in 2020 because of crashes in the old. And I won't upload an individual old version without the permission of 고기육수. Also 고기육수 seems to be offline for a long time, I cannot contact him, so I have no other place to comment these things.

I just ... feel a bit sorry about the lost of old version, since it provide individual normal quests in town area, just like other areas, thus make the game become more "colorful".

Besides I just hope 고기육수 could know the reasons and feel relieved, since those crashes in the old version are mainly NOT his fault. He did made a great mod, even for the old one.

Sorry for these long comments. I will move all these comments to the discussion area above, and won't talk about these any further.

@Cathelia Samicora
Well, this mod is opensource since the 2020 rework (words of the author himself) so a rogue patch or a new upload is completely fine.
Tbh I'm curious to see how was the original mod, the current one is already enjoyable :/

@Yogurt-Sothoth
The old version has added random generated quests to the town area, but because of some crash bugs caused by "curio summoning codes such as shambler altar in the town area mash files is missing". The creator cannot find solution, thus had to abandoned the random generated quests, only the non-random quest known as Rift Dungeon remains.
I'm sorry that recently there might be no plan to rework this mod.

@Cathelia Samicora
I got installed an old revision of the mod (November 2018) and the fix you suggested before was already present in the .mash files (at the very bottom).
Weird. I don't understand why the author scrapped that version then...anyways, thanks for your time and advice. I'm glad to know I can keep the mod in my game without worrying for that nasty bug.

@Yogurt-Sothoth
You are welcome :-)