This is to outline what the code inside MO that generates these PMOP messages does and why.
I am not a programmer, this my rudimentary understanding of the code as I read it. This description will be revised upon further understanding or correction from others.
Firstly your computer will not explode, burst into flame or otherwise if you disregard those messages, your game however MAY suffer from some bugs, unless you absolutely know what you are doing with those mods.
The official stance for MO is to allow the MO warning dialogue to have the mods (left-hand pane) to be 'fixed'.
STEP guides may provide another arrangement and therefore you can disregard any potential errors.
PMOP = "Potential Mod order problem"
The operative word here is 'potential'. There are no deep, fancy searches made inside the contents of your scripts to determine whether a mod should or shouldn't be where it is placed, that is for the user to determine.
The steps involved are as outlined here:
- MO searches the list of mods for those that contain scripts (*.pex) and uses ONLY THOSE mods for the next step
- Using the order of the plugins (right-hand pane) as the desired order, it presents a series of moves to arrange the mods (left-hand pane) to match.
- A dialogue is presented that shows the mods that don't match the order as expected and the steps needed to arrange correctly.
MO then checks the order again and if all is fine, the error message is removed.
Note: The code needed to slimline these steps would be complex and extravagant. Often the provided list of steps needed to 'fix' the mods can be done by moving just one or two, not all of them. However, doing so will not break your game.
After installing your mods, it is usual to arrange the plugins into the correct order, either manually or with a tool like LOOT. LOOT uses an extensive list of sorted plugins to assist this process, there is no such such list for mod order in MO's left-hand pane.
It is after this step the order of your mods needs to be examined. Do it manually or allow MO to aid you, but you must also ensure the left-hand order is correct.
Why does MO make these checks?
As the dialogue says:
The conflict resolution order for some mods containing scripts differs from that of the corresponding esp.
This may lead to subtle, hard to locate bugs. You should re-order the affected mods (left list!).
There is no way to reliably know if each of these changes is absolutely necessary but its definitively safer.
Isn't that something we all want, a reliable working game? There is no nefarious intrusion on your modding going on, simply another tool to aid in ordering your mods.
Doesn't LOOT already do this for us?
No. LOOT deals only with the plugins (right-hand pane) and therefore has no possibility of handling the order of the mods. (left-hand pane)
I didn't have to worry about this with NMM/FOMM/Wrye Bash. What's the big deal?
That's right, you didn't. You also didn't have the ability to move your mods that contain these assets around to provide the best installation. All other managers rely on the actual install order and if you make a mistake, you have to start over. Because MO allows you to do this it also provides a tool to check for any errors.
* Note the proviso mentioned in the first comment below.
Okay, so if I do ignore MO's warnings, what will happen?
Good question. Depends on what is provided by the 'winning' mod in the conflict. Remember all MO is doing is checking for the presence of scripts that are the same, it makes no line-by-line comparisons of the actual script code.
If the scripts are identical, nothing will happen. If the scripts are different then the desired effect will either be missing or broken somehow. MO doesn't know there will be a problem, that's why it is called a "potential" problem.
Yeah, yeah, but these messages annoy me.
Hmm... easily offended are we? Not to worry, MO also allows you to disable ALL helpful messages if you desire, just examine the 'Settings'.
So, next time you see this error dialogue, stop to think what is actually being offered to you.
Here is a helpful reminder to re-examine the list of mods/plugins and check if there are issues.
Have a look at the amount of code involved in the LOOT project to see what is needed to have software make all these checks for you, and that is only for checking *.esp/esm conflicts. Imagine what would be needed to create code that checks the internals of scripts or other assets to order them correctly!
While MO isn't quite performing those sort of tasks, it is doing the next best thing - warning of potential problems!