Borderlands 2 downgrade below February 2020 Update (and some other fixes). Does not work for EGS version!

The guide is intended to provide Windows-Mac-Linux coop. Mostly. Not only.
Info for TPS downgrading is here too.

Introduction

Coop is realizable when all players in a lobby have same versions number. You may see this number in the bottom right corner of the window shows when you go "Matchmaking" -> "Match browser" from the main menu.
2020 year's updates haven't been ported to Mac edition of Borderlands 2. Same for the Linux one, but it is out of date even longer. So downgrading the game on Windows is the direct (and likely only) way to OSs' crossplay.
You can rollback to the previous (1.8.5) version which allow you to connect with Mac players, or the older (1.8.4) version to play with Linux users.
Steam Play with Proton allows you to play the Windows game version directly on Linux so you have no need to game downgrade.
To recover the current version use "Verify Integrity of Game Files" in Steam.

More help information you can find there:
(see pinned posts and existing chat, ask own questions rather here in comments)
https://discord.gg/aspyrmedia

How to downgrade?

NOTE: For Linux-Mac coop you need to use Proton on Linux then rollback it to 1.8.5.
NOTE 2: After doing downgrade you won't be able to connect with other Windows-players who didn't commit the rollback.

1. Download the archive with the files of:
   
   • version 1.8.4 (to coincide with Linux) there[drive.google.com] or there[yadi.sk];
     
   • version 1.8.5 (to coincide with Mac) there[drive.google.com] or there[yadi.sk].
2. Go to Borderlands 2 game location folder (you may Right click on the game in the Steam Library and choose Manage->Browse local files);
   
3. Copy/paste the archive content to the game location folder (when Windows ask, choose to REPLACE the old files with the ones that you copy);
   
4. Now you can run the game.
   ALARM!!! After replacement with 1.8.4 version's files the game won't start the first time. And the second too probably. Steam somehow patches the main executable so after a few starts and some glitches the game will run properly.

Questions

• Where to find same thing for Borderlands: The Pre-Siquel?
  There[drive.google.com] are files to rollback. Procedure is the same.
  ALARM!!! It has the same running issues as 1.8.4 B2 rollback. The game will start correctly after 2-3 tries.
  Also see discussion.
  
• I had committed downgrade and yesterday everything worked fine but today the game doesn't even launches.
  Did Gearbox make a new patch? Rollback should be redone after every game update.
  Otherwise there and there may be some ideas.
  
• I've downgraded the game rollback to 1.8.4 and it crashes after launcher closes.
  It's normal. Steam somehow patches the main executable during a few starts so the game will run properly in the end.
  Also you may go to "<Borderlands folder>/Binaries/Win32/" folder and start Launcher.exe or Borderlands2.exe manually. A few times too probably.
  If it doesn't work, see the previous paragraph.
  
• Lost speech sound in the Commander Lilith DLC on non-Eng versions.
  See there.

Do not pass by!

Does someone remember Angel and Lilith hologram looking before the 1.8.5 patch?
Nowadays you can see bluey-blurry-striped holo (as example, of Angel):











But it was not always like that. Would you glad to see and feel the depth of the woman glance? Doesn't she deserve to show her artificial Intelligence lively beauty to her subservient?












To admire the true perfection, download files there[yadi.sk] or there[drive.google.com] and put them into "<Borderlands folder>/WillowGame/Movies/" folder.
(Does not require the whole game downgrading.)
 

[BuckyBaggot]

Will I lose access to downloadable content?

[Espio]

Nevermind, figured it out. Big stoopid.

[Espio]

Anyone else get into a "Downloading Updates" loop after quitting single player once downgraded? P annoying, especially when needing to re-roll vendor inventories.

[Wolfwood]

Fuzewawa
Yes, it's possible. You need at least depots "base content OS X" 221701, "executables OS X" 221702 and "english OS X" 221703. Everywhere you need manifests of 29 October 2015, for 221701 it is 1060609375334598826. But also you need base depot for every DLC you have. They named <smth> Content OS X.

[Wolfwood]

Majik_Ninja The old versions (below 2.0.0) dont have Shift

[Fuzewawa]

Following these guides :
https://steamcommunity.com/app/588650/discussions/2/1627412105598468072/
and
https://steamcommunity.com/sharedfiles/filedetails/?id=2353930763
and
https://steamcommunity.com/sharedfiles/filedetails/?id=1086279994

[Fuzewawa]

Trying "download_depot 49520 221701 6422949341526953102"
or
"download_depot 49520 221701 1060609375334598826"

[Fuzewawa]

Hello again. I'm now trying to downgrade the Mac version to 1.8.4.
Trying the depot method. Is this still possible to downgrade a game looking at old depots and if so, does someone know the name of the old Mac 1.8.4 depot ?

https://steamdb.info/app/49520/depots/

[Majik_Ninja]

I did this and now my SHiFT won't connect idk why

[bezoldeffect]

Thank you!