Play old GMod demos / Or how to legally download the previous version of GMod

About every year, developers did changes on gmod binaries / libraries and that affect demo (.dem) files. So demo recorded in 2017 was unavailable now because of changes in DT system or in something else. I have tried to open them, using different tools, but no result. Demo file is bound to gmod version, because it store every activity which happend ingame, such movement, voice and chat data, every player nickname's, steamid's, even spray data. And ideal way to load them for now is download older version of game. I have tried to find old pirate builds, but failed(cuz they are broken), but i did find steam console command option and history of gmod depots.

Getting manifest ID for older GMod version

We need to find depot manifest id for required GMod version. Required get content and executables.
Content depot:

• GMod content manifest ids[steamdb.info]

Executables depot(select for your OS):

• GMod Windows executables[steamdb.info]
  
• GMod Linux executables[steamdb.info]
  
• GMod OSX executables[steamdb.info]

More info if need is here - https://steamdb.info/app/4000/depots/

Downloading depots

Firstly we need to open steam console. Quicker way is this link - steam://open/console
Better to see guide below.
https://steamcommunity.com/sharedfiles/filedetails/?id=873543244
For example I need GMod version June 16, 2014. Manifest ids are 1264754226376602464 for content and 6796453289010552339 for windows executables.
Execute next commands:

• For content

  download_depot 4000 4001 1264754226376602464

• For executables (Replace 4002 to 4003 on Linux, 4002 to 4004 on OSX)

  download_depot 4000 4002 6796453289010552339

Game ID is 4000. Depot ID is 4001 - 4004.
Answer should be like that:

• Downloading depot 4001 (2030 MB) ...
  
• Downloading depot 4002 (60 MB) ...

Be careful, if you exit steam, you will need to download them again. Download will be displayed in steam downloads. Usually takes ~ 20 minutes to load.
After complete you will see something like that:

• Depot download complete : "S:\Program Files\Steam\steamapps\content\app_4000\depot_4002" (139 files, manifest 6796453289010552339)
  
• Depot download complete : "S:\Program Files\Steam\steamapps\content\app_4000\depot_4001" (2293 files, manifest 1264754226376602464)

Launching GMod

After downloading depots we should open folder contains them. For me its

S:\Program Files\Steam\steamapps\content\app_4000\

Now merge that folders into one, for example create new folder and put contents from "depot_4001" and "depot_4002" to "Gmod2014".







You can't launch gmod without license, there is two ways to launch it:

• Better way. Create bat file in folder which contain hl2.exe. Open bat file with notepad or another text editor and put these:

  start hl2.exe -insecure -steam -sv_lan 1 -console -noworkshop exit

  And every time open older GMod with that bat file, instead of .exe.
  
  
• Rename original GMod folder to any name and put downloaded GMod folder in same directory, rename that folder to GarrysMod. Launch throught steam. Do not forget to return the original game folder to its place!

Playing demo

Demo will play in any case if game engine version is correct. There is only one requirement - map where demo was recorded. Better result if you had same addons & mounted games as on demo.
If demo won't play, look console:

• If you see something like that

  RecvProp type doesn't match server type for DT_BoneManipulate/m_BonePos

  so engine version differs with current, you need to download another, earlier than demo was recorded.
  
• If bad map, so you just need that map to be downloaded. Google it.
  
• In other cases, verify your addons, they shouldn't conflict with each others and GMod lua files. Check is map valid, just create new game with that map(if demo is multiplayer, create same), if there no bugs, try to record new demo(1-5 secs), stop recording, disconnect(maybe not) and launch playdemo. Also may help if you fill server with bots, spawn some props, vehicles and etc. (That helped me once)

If demo crashes game, it seems that demo is broken or too large. It can be also engine bugs and other stuff. There is no solution.

Commands to record/play demo

record <demoname> - records a demo in GarrysMod/garrysmod folder. Output file will be <demoname>.dem
gm_demo - allias of record?
stop - finish recording a demo

playdemo <demoname> - play demo from GarrysMod/garrysmod folder. Also can play demo from folder.
stopdemo - stop playing demo
record_screenshot - take screenshot from active demo playback

gm_demo_to_video <demoname> - opens menu, allows you to play demo and record it with selected codec into video file with selected settings. This will quickly play demo and don't provide demo control options and etc.

Controlling demo:

• Shift + F1 - View/Debug options
  
• Shift + F2 - Playback options

Conclusion

This method helped me play old demos of 2014-2017. There are a lot of memories in them and I did not find manuals that would help restore them. As a result, I turned out to play 90% of the saved demo files.
Press Rate if it helped you.

[Jack Parker]

Still work?

[tauon gaming]

when i download a manifest it says there isn't one with that id as if it was deleted by garry

[UnkN]

Try run it from steam (as add custom game) with -steam and -insecure startup commands, otherwise you should find pirate version. I cant say why it doesn't work, since joined gmod after gmod13.

[UnkN]

No way, they're using another source engine. I'm not sure, but you can find old versions of gmod (from 9 and upper) in internet. In theory they can be also played by compiled source engine 2007 with modified source code to breach security (HL2 will cause error because of mismatch versions of vis, vbsp and etc.)