So, I got stuck for almost a year on the same Origin version. The client was correctly finding there was a newer one available, but every time I restarted to update.. it simply launched normally as if nothing happened. And I tried to get out of this situation by studying its behavior and logs in %PROGRAMDATA%\Origin\ (note: cleaning everything, including also stuff in %LOCALAPPDATA% and %APPDATA%, didn't help at all)
Origin::Services::SelfUpdateService seemed fine before restart.. The only somehow suspcious thing was bootstrapper complaining about Error OpenSession: failed to send request on the initial online version check. Maybe they slightly changed API?
Anyway, long story short the only thing I could come up with after a day of fights was that UpdateTool.exe is supposedly launched with either /SelfUpdate /Beta:false /Version:updated.new.build.version or "\"X:\whatever-folder-origin-is-installed\Origin.exe\" /Installed:updated.new.build.version /StartClientMinimized" /FinalizeSelfUpdate parameters.
.. And today I found it's probably deprecated completely, since a normal working update seems just to care about starting this now "C:\ProgramData\Origin\SelfUpdate\Staged\OriginThinSetupInternal.exe" "/InstallPath:X:\whatever-folder-origin-is-installed" /locale:it_IT /Version:updated.new.build.version /DesktopShortcut:false /StartShortcut:false /Autostart:false /Autopatch:true /Autoupdate:false /TelemOO:false /Beta:false /IsBetaBuild:false /Handoff /WaitForExit /UpdateDataSource:download
I also found out just about every Origin version is available from here or here.
And I spotted games themselves are served from similar positions (e.g. this is BF3 AK expansion, while this is some whatever Apex thing)
I am wondering (provided one had some way to force auth), if older versions of games couldn't still be available?