(UPDATE: when I originally posted this I thought here were some potential issues with vanilla Oblivion too but as it turns out the vanilla issues were some left over from previously modding the game, the updated post below now reflects this new information)

Hi,

While working on my Oblivion Modding Guide I've run into issues running TES4LODGen and some things. I've spent the better of the last week investigating these issues and learning more than I wanted to know about Oblivion modding so please if you reply to this thread, thouroughly read my post before doing that, thank you!

TL;DR GOG version of Oblivion (offline installed and Galaxy installed) doesn't set proper Last Modified times for the ESM/ESP files which potentially results in all sorts of issues, from unmodded game not starting to strange errors using mods and modding tools. To workaround these issues search for "workaround" below.

Long version:
Oblivion (and FO3 and FNV for that matter) relies on the Last Modified file dates in order to decide in which order to load ESP/ESM files (and I think the same happens for BSA files and unpacked resource files but the latter is easily fixed by using ArchiveInvalidated!.bsa solution employed automaticaly by tools like Wrye Bash). Yes, this is a VERY DUMB thing to do but nobody is going to change Oblivion now to fix that, that ship has long sailed.

Tools that need to read the list of ESM/ESP files to process them in the order that Oblivion would, also rely on Last Modified ordering (obviously). Tools that allow one to change ESP/ESM file order (Wrye Bash, BOSS, LOOT, OBMM) automatically update the Last Modified times of files to reflect the desired order. They start with whatever Last Modified date Oblivion.esm has (since that file is ALWAYS loaded first and dependent on by every other ESP/ESM file) and then they add one minute to the last modified time of every ESM/ESP file following Oblivion.esm.

When installing Oblivion from my disc GOTY version, here's how the Data directory looks, pay special attention to the Last Modified column: http://imgur.com/a/ZMDQu
As you can see all BSA/ESM/ESP files have Last Modified times of sometime in 2006. What's more, if you sort by Last Modified time, the dependencies between the ESP/ESM files are correct (ie a file with a more recent Last Modified time only depends on files with older Last Modified times). For example Knights.esp depends on Oblivion.esm which is older in terms of Last Modified times. This is required in order for Oblivion to start and function properly.

If I run BOSS now, it will pick the Last Modified value of Oblivion.esm and then change the Last Modified values of every ESM/ESP that follows it (in the BOSS generated order) to be a minute apart.

Now, if I am installing Oblivion using the latest offline installer (1.2.0416 CS), this is how the Oblivion/Data directory looks like: http://imgur.com/a/SGXGr

You may wonder, wait a second, where are the Last Modified values, they aren't being displayed. That is true, for some reason, File Explorer in Windows 8 and up (see this post: https://answers.microsoft.com/en-us/windows/forum/windows_8-files/pre-1980-modified-date/f17edd9a-44d4-48c5-aa00-d6c619f2765c) do not display the Last Modified value if it's older than 1979-12-31 23:00:00... no idea why. If we right click on a file (for example Oblivion.esm) and go to properties we can see the Last Modified value, for example: http://imgur.com/a/Wd01E

And that seems to be the case for all the other ESM/ESP/BSA files, they are dated sometime in 1969-1970. You can get the full list of dates by starting Wrye Bash and looking at the Mods tab: http://imgur.com/a/vFqFy

Alright, but while those dates seem a bit too old at least the ESP/ESM files look ordered correctly in Wrye Bash. That is true, however, all tools based on xEdit (ex. TES4LODGen) seem to have issues with these very old dates. If I run TES4Lodgen with the files as shown above, then it will display a completely different (random looking) order of ESM/ESP files, tho it doesn't necessarily fail because of it, not yet at least. Note the random order of ESP/ESM files from its log: https://pastebin.com/6wqcSz1f I reported this issue to TES4LODGen people but they do not seem very interested in fixing it, considering that other versions of the game (disc and Steam) don't experience this problem.

If I install the simplest mod, Unofficial Oblivion Patch and then run BOSS this is the Mods tab in Wrye Bash (note the order and the Last Modified values): http://imgur.com/a/KKYXQ The dates start immediately after the original date of Oblivion.esm and then are 1 minute apart, that was done by BOSS. If I run TES4LODGen now, it again seems to try to load the ESM/ESP files in random order only this time that results in actual failure: https://pastebin.com/hQ377T3y

If you install mods and need to run any tools based on xEdit (including TES4LODGen) you are very likely to run into this error. It appears that xEdit incorrectly orders the ESP/ESM files when those files have very old dates (older then 1979-12-31 23:00:00). Combined with the fact that GOG offline installer sets Oblivion.esm to 1969-12-31 it means that using this version of Oblivion you will likely run into this problem. This is likely the result of some bug in xEdit (Wrye Bash, OBMM and other tools correctly process the order of ESP/ESM even if the dates are old), likely something to do with Windows 8 and up (because File Explorer too has issues displaying those old dates) but it's much less likely that the tools authors will fix it than that GOG should fix their own release to do what other releases are doing.

However, even if you run into this issue, there is an easy workaround for it: set the Last Modified value of Oblivion.esm to something more recent (ex. 2000-01-01 00:00:00) and then run BOSS which will order the other ESP/ESM files and automaticaly update their Last Modified times to follow Oblivion.esm. To set the Last Modified value you can use something like Attribute Changer (get it here: https://www.petges.lu/download/) or you can set it directly in Wrye Bash if you're using that. Wrye Bash has even more ways to fix this, you can select all files in the Mods tab, then right click and go to File -> Redate, then input "2000-01-01 00:00:00") and it will redate all files starting with that value. It will look like this: http://imgur.com/a/fPWo0 Now if I start TES4LODGen it's working fine and the ESP/ESM order it uses matches identically the Wrye Bash order: https://pastebin.com/5GPrwHfS

After this, I also went and reinstalled Oblivion using GOG Galaxy. Here things are relatively random. Sometimes the file dates are set like in the offline installer, 1969-12-31..., and then you run into the xEdit/TES4LODGen issues described above, other times I simply get the download times, for example: http://imgur.com/a/mrF3u

When the latter happens, even if the last modified dates of files is relatively random (whenever they happen to be done downloading) there shouldn't be any TES4LODGen issues becuase you probably also run BOSS/LOOT that will redate files in the right order and TES4LODGen works fine with dates newer than 1979-12-31. One might think that the vanilla game might run into issues because Oblivion.esm might have a date after an ESP file that needs it (ex. Knights.esp) but that actually isn't a problem because Oblivion seems to always load the ESM files first (and vanilla Oblivion has no interdependency between the ESP files, they all just require Oblivion.esm to be loaded first).

My request for GOG: please set the BSA/ESM files to have Last Modified dates of "2006-01-01 00:00:00" (which is slightly earlier than the earliest Last Modified value in the disc version, so mods made to work with that version should still work with the earlier date) and set the times of the ESP files to be, an hour or a minute apart and their Last Modified based order should match the order given by BOSS, like here: http://imgur.com/a/0Drz7

I believe that by doing that, it will make it work for all users that otherwise potentially run into problems as explained above.

PS: Note that above when I installed GOG Oblivion I used the latest version, the one with CS at the end. The CS update changelog mentions something about adjusting the file times but it doesn't seem to be always working. Even when it does all it does is to set the BSA file times to "2006-01-01" while most of the issues I listed above appear because of the wrong ESM/ESP file times, not BSAs. Having wrong BSA can also result in modding issues if you don't use the ArchiveInvalidated!.bsa method of overriding game textures, but any good modding tool (Wrye Bash, OBMM) will use that method anyway so the BSA times issue is a much smaller problem than the ESM/ESP issue which affects even vanilla/unmodded Oblivion.

Thanks for the guide and the explanations!
To the moderators: This post should be stickied - at least until GOG comes up with a patch for the latest patch.

Looks like BOSS requires internet access to do its job. When I ran BOSS for the first time, I blocked the attempt to access the internet, and the program produced an error message. The second attempt, with internet access enabled, worked. I find it hard to understand why a utility like BOSS needs to access the internet.

FWIW, according to reports on the mw/reddit, Galaxy also redates Morrowind esms to a current date.

How about an option to download the current master list then? Shouldn't be difficult: Download file, put in correct folder. Unless the programs are designed to fail without an internet connection... in which case my already lukewarm interest in them evaporates.

OK - thanks. I trust that it's not used for any commercial purposes.

You can do that for LOOT at least (and tell LOOT not to try and fetch a newer masterlist to not get errors about a missing connection). I haven't used BOSS since LOOT was released, but I know some other guys took that project over and did some more development on it too, so I don't know what the current state of BOSS is. You can contact the current developers of it and ask them about it though.

It's not the smartest idea Bethesda ever had, that's for sure, and starting with Fallout 3 they seem to have given up on that crap and instead obey the order from the Plugins.txt file. But unless GOG changes that algorithm/code in Morrowind and Oblivion (I doubt it) they have to fix Galaxy to be able to set specific file timestamps on downloaded/installed files. But I don't know how much work would that entail, it doesn't sound like much (just call some Windows function to set the Last Modified time) but it would require that the Last Modified file property is being stored on Galaxy servers and made available to Galaxy clients (plus something to also handle setting desired times when using backup installers). And all that would have to be done just to support modding for 2 games, maybe they don't think it's worth it. I still need to file a ticket about this...

Ah, I love it when the uninformed make comments instead of asking questions..

Firstly, thanks Dizzy. I agree this post should be stickied until GOG sorts this out. This is ultimately a problem they created by not understanding the game they were (re)releasing. Thank you also for the link to your guide. I'm finding it very useful! No, of course not. Go visit the sometime, or read up on it if you're worried.<div class="quot quot_text normal_color "><div class="small_avatar_2_h"><img src="//images.gog.com/324b1e756c7610a7af6c6591ae7ceab1e18ca2ca661c351b1face5ea86c845e3_avm.jpg" width="16" height="16" alt="avatar" /></div><span class="quot_text"><span class="quot_user_name">SeduceMePlz: </span></span>How about an option to download the current master list then? Shouldn't be difficult: Download file, put in correct folder. Unless the programs are designed to fail without an internet connection... in which case my already lukewarm interest in them evaporates. <a href="http://www.gog.com/forum/elder_scrolls_series/gog_doesnt_set_proper_last_modified_times_on_esmesp_files_which_results_in_modding_and_vanilla_i/post5" class="link_arrow"></a></div> Already implemented. Have you ever used BOSS? The GUI has an option to download the Masterlist. Uncheck it &amp; doesn't try to make any connections. Look under Settings and you can see exactly where it's trying to download the Masterlist(s) from, and even lets you change it. You can also download the current Oblivion Masterlist from [url=http://www.nexusmods.com/oblivion/mods/45765/?]here, or here. Both good places to also read up on BOSS. It's not designed to fail without an internet connection so your lukewarm interest should remain tepid.... :/ You can do all that with BOSS too. Frankly, BOSS is the community accepted best sorting tool for Oblivion. LOOT has made numerous errors, both in my experience and many other's, and is not used for Oblivion by most experienced modders. Don't get me wrong, I'm not in any way bashing LOOT. It's great for Skyrim, FO, etc., just, for some reason, not Oblivion. Let me also express my thanks for your contributions to LOOT!

Sadly there's only one maintainer of BOSS at the moment, (that I'm aware of) and he's recently had a lot going on in RL that's prevented him from making more updates. However, given that the vast majority of mods for Oblivion were made prior to the last BOSS Masterlist update, it's still an essential tool. If you or someone you know is interested in helping keep the Masterlist updated, shoot a PM here. (Much appreciated.)

Back to the topic at hand; Dizzy, do you know if this redating thing is only with the version that includes the CS? I downloaded mine (stand-alone), it didn't have the CS included, and the timestamp was, oddly enough, 12/31/2000. I haven't downloaded the Galaxy thing, as I'm averse to unnecessary software. Does it automatically update the games you've purchased?