Update July 15 2020: I tried uninstalling and removing ALL files related to civ 5 on my computer. I then reinstalled civ 5 from steam and redownloaded all my mods from in-game. I selected MEO, MECSs, MES, LOTRC, and infoaddict.

I then tried to replicate the bugs and I tried both with Directx 9 and with Directx 10/11. I played a game as Isengard and saved right before building a fair ground and lighthouse, and used this save for all my observations.

With both versions of Directx, I could not replicate the orc spearman bug - it was working perfectly normally both times.

I successfully built both a fair ground and a lighthouse in this save with Isengard, and then I reloaded and did it again with the other version of Directx. Both times the game continued with no issue. The buildings showed up on the game map graphically and in the city view screen.

I then tried bumping up all of my graphics settings to the max (they had been fairly low) and restarted the game twice with both versions of Directx AGAIN. (I put anti-aliasing 8x MSAA, GPU texture decode turned on, plus all settings set to high. Also, I had VSync turned on the whole time in all 4 tests). In both of these new tests I replayed the turns building the lighthouse and fair ground and again no problems. Again the orc spearmen were fine too.

Seeing your comment, I wondered if it was civ-specfic, and tried a game just now where I sprinted to a lighthouse as Isengard -- crash. I also have Intel graphics, and haven't experienced any issues with orc spearmen.
A completely unrelated thing I noticed: Peace of Uinen pantheon belief says it gives 2 faith to lake and oasis tiles, but in a game I noticed the bonus applied to oasis tiles only? There was no faith icon on lake tiles, and working them did not change my faith per turn.
I love this mod, and thank you for your dedication to it.

Thanks for that additional info, you probably caught a feature that I forgot to actually implement.

But yeah sorry I haven't figured out the bug.

So the implementation is there but I confirmed in-game that it doesn't work. This is probably because lakes are technically defined in a "fakefeatures" table and don't count as actual features. I am currently thinking of how to change the belief to no longer include lakes and will post the update to the workshop when done.

edit: ok, changed it to just +3 faith from oases

Okay,
I did a little test with orc spearmen.
I started the game on DirectX9 and .... everything works fine.

So I started on 10/11 and there was a bug again.

At first I thought it might be something with graphics settings because on the DX9 everything was LOW and OFF with resolution 1366/768 (on DX10/11 - High, ON and 1920 x 1080).
So I copied graphic settings from DX9 do DX10/11 but there was still a bug with orcs.

I copied also settings from DX10/11 to DX9 and all was fine.

So it seems there is some issue with spearmen/pikmen orc problem with DX...


If there was and bug only on my computer I would think that I have something wrong but other mods as well as the CIV V itself goes well (and also other more demanding games).

I do not meet yet a bug with lightouse or any other.

https://imgur.com/a/LFKmCqr this is how the pikeman bug looks like. The screen is not constant black - it flashing - only when i look on pikeman. On other area everything is fine.

I saw an umbar city with name Txt_key_city_name_mec_ethir_anduin. Doesnt do anything, just strange city name. Just want you to know.

also didnt get greate person from liberty closing, dont know if it should be like what.

@irnf8u143nfu9rq3 I have an idea about the cities disappearing and sometimes crashing the game. I think it might be cultural building variations causing the problems when the ME civs have their own defined cultural variation but no buildings. I'd suggest overriding the buildings that have cultural variation. I might look into this at some point. I hadn't heard about the light house before. just the circus.

1) Asalut thank you very much for that information and for the screenshot!! That seems like a big breakthrough. And it's also very informative because before I didn't really know what the bug actually looks like. It's also good to know that not everyone is getting the building crash bug.

Has anyone else with the spearman bug tried directx 9?

2) nik13 you found a misnamed city name from the original MEC. I had known about this but forgotten about it. Basically the city name "Ethir Anduin" has a mispelling in the name of the variable used by the game logic. I just fixed it and will upload a new version soon.

And the second thing is not a bug. I purposely changed the liberty finisher (as well as some other policies). You should see this if you look at the help-text in-game (hover over the liberty tree). The change is also described in the documentation under the "policies" section as well as in one of the pictures in the workshop description.

3) Yenyang that's a good point. In fact, I had noticed that when I built a lighthouse in my test game, even though the game didn't crash, it did switch the city to become invisible (this did not happen with the fair ground / colosseum though). So maybe the reason some people are getting this bug, is that for some reason their game does not "allow" the invisibility bug, and instead just crashes. So maybe they are linked and this clue could lead to fixing both. I will look into it.

I don't know if I can make any of these changes until the weekend because I'm very busy right now with real life. I'll post an update.

Thankyou. I think the reason why I didnt see it was russian language in my game. Most policies still be in russian, and I saw Umbar Great general Guderian (in russian, to). So I think that I should change langunge to see differencies, but I dont know how. Also, Ive created fair ground without crashing.

Just a quick review i did of Civ5's building xml file. Shows the lighthouse has <ArtInfoEraVariation>true</ArtInfoEraVariation> which might be the problem with your mod because you added Eras.
I may have circus earlier but it's possible I meant COLOSSEUM . because the COLOSSEUM has <ArtInfoCulturalVariation>true</ArtInfoCulturalVariation>

There are three types of art variations for buildings
<Column name="ArtInfoCulturalVariation" type="boolean" default="false"/>
<Column name="ArtInfoEraVariation" type="boolean" default="false"/>
<Column name="ArtInfoRandomVariation" type="boolean" default="false"/>
I'm fairly sure they are responsible for our issues with buildings disappearing. I think your instinct that this leads to some games crashing may be true. I have consistently seen certain players complain about crashing on a certain turn around 100 and they are usually on macs.

My best guess on how to fix this is to set the artdef for these buildings to NULL or empty

could someone please inject this code into their mod? and tell us if that fixes the problem.
preferably into the file at ...\Lord of the Rings Civ5 (v 1)\xml\mec_unitartinfoculturalvariation.xml

<Buildings>
<Update>
<Set ArtDefineTag="NONE"/>
<Where ArtInfoEraVariation="true"/>
<Set ArtDefineTag="NONE"/>
<Where ArtInfoCulturalVariation="true"/>
</Update>
</Buildings>

Make sure the code is injected after </Units> and before </GameData>

Potentially big news. Let me walk you through the observations. So remember that for me, I had been getting disappearing cities when building lighthouse but not when building colosseum (fair ground).

When I set their artdefinetag = NONE my cities disappeared when I built EITHER the colosseum or lighthouse. I then tried turning off all of the artinfovariations by setting them all to "false" where it had previously equaled "true" (both for "era" and "cultural"). That again resulted in my cities disappearing by building either one. Then I tried simply changing artdefinetag to something that already exists: I changed the artdefinetag for colosseum to = the market artdefinetag. That caused my city to disappear when building the colosseum (fair ground) where it previously had not disappeared. I changed it to library and got same result, even though I had never previously had problems with libraries, markets, or colosseums.

Then I realized that when setting the artdefinetag for a building, it needs to be set to something that has the same artinfovariation settings. What I mean is that for example since colosseum has artinfoculturalvariation = true, its artdefinetag will only work if set to one of another building that also has artinfoculturalvariation = true.

Since nobody has reported city disappearing right at the beginning, the implies that the palace art works and does not cause disappearances (for whatever reason). It just so happens that the palace building has artinfoculturalvariation set to true. So I set the artdefinetage for colosseum to = palace. I also set the artdefinetag for lighthouse to = harbor, since harbor also has artinfoeravariation just like lighthouse.

When I did this, sure enough I was able to build both buildings without problems. The fact that you will have "duplicate" palace and harbor artdefinetags doesn't seem to matter and doesn't cause any immediate bugs. I built a harbor in the same city with the lighthouse and it did not cause a duplicate city-harbor-art-thing, it just stayed the same. So it appears to all work.

Furthermore, as I teched up and played through a game I noticed that the AI's cities were not disappearing either - at first. But unfortunately, as the game went on slowly one by one a couple AI cities started disappearing. It never became a majority of the cities on the map but just 2-4 at most.

I used spies to figure out that these invisible cities were NOT caused by buildings - since they were usually new cities and some of them did not even have buildings yet while invisible. Also, sometimes some of them became visible again for a few turns, or were visible when zoomed out or from certain angles but not when zoomed in. Furthermore, in the late game eventually my capital became invisible, but it happened in the middle of building a wonder so it was not caused by any building.

Conclusion: There are two distinct causes of the city invisibility bug.

One is that it can be caused by building certain tricky buildings that have artinfoculturalvariation or artinfoeravariation, and there seems to be no way to fix it other than change the artdefinetag to something else (luckily, this seems to work by changing to the palace and harbor).

The second cause just seems to be entirely random and there's nothing at all you can do about it, since it has nothing to do with the buildings in the city.

Great work Irn. thanks for trying my suggestion. It's too bad that didn't work.