Possible duplicate of #18
I suppose that's fine IF Proton came with mono and that removed the need to install the .net redist package or whatever for all games.
However, Wine 3.18 already includes one .net fix anyway that should help in some situations so its not like they aren't do this anyway. There's a lot of stuff to do so it takes time.
https://www.winehq.org/announce/3.18
45680 Microsoft .NET Framework 3.5 (SP1) fails to install in 64-bit WINEPREFIX
Also mono does not work for all games, for example, Space Engineers won't start with mono. Mono needs to be removed and .net 4.7 needs to be installed instead, but yes mono would definitely help.
AFAIK, Mono doesn't work together with .NET. With this in mind, I ponder, what happens when you start a game from Steam? It installs all the prerequisites... Meaning that .NET will be installed as well(if needed) therefore, Mono might be unusable. Not to mention that it's very unfriendly for the user to see a installation failing(or not even installing, like .NET 3.5). Although it would be awesome to have some workaround, without using any .NET.
Edit:
Forget about this part, as Proton "uses" Windows 7, meaning that it fail by saying that it's incompatible.
(or not even installing, like .NET 3.5)
Possible duplicate of #18
No it is not, mono is an attempt to duplicate the functionality of the .NET framework, a mostly successful attempt, yet not successful enough for our purposes in gaming.
It's worth mentioning that there's a regression in proton, where installing .NET framework 4.6 or higher does not work in proton 3.16 (last worked in 3.7 I think). installing .NET framework 4.0 does however work.
FYI: I've gotten 3 games (DmC, Brothers:ATO2S, and Killer Is Dead) to work by forcing winetricks to install dotnet40 a 2nd time whenever I got the can't find ngen.exe error after the 1st time.
Maybe that has to do with some async operations? I've read on the Wine Bugzilla that that's what's preventing the Bayonetta config file from being stored.
As others mentioned: There's also the general problem that the Proton prefix defaults to Win7 which prevents dotnet35 for example from being installed (Win7 comes with it pre-installed). Example: the Batman games. For Arkham City I literally only had to switch the Windows version of the prefix to WinXP to get .Net to install through Steam's own pre-launch setup and run the game. Took about 20 min. though.
proton 3.16x1 2018-11WINEPREFIXx1 2018-10mscoree.dllx1 2018-10
Feature Request
I confirm:
contain this feature already.
Description
Installing .NET Framework into wine prefixes can be a challenge. Sometimes using winetricks (or for proton, protontricks) will work, but usually I've found that it does not, in those cases the recommended solution is often something along the lines of "Set the prefix to Windows XP mode, download a dotnet framework standalone installer, and install it" but even then, it's not guaranteed to work.
I frequently get failures where mscoree.dll is missing or errors where ngen.exe is not found when I try to deal with this.
Hopefully something like an automated script that detects if a game's installscript is trying to set up .NET redists, intercepts it, and installs it some other way that's guaranteed to work instead. Or alternatively setting up a list with ids of games that require it with some method to do it manually in case the game is not on the list.
Justification
It is already poorly implemented in winetricks, but the number of games that require NET Framework is awfully high, and the same number of games will typically fail to install NET Framework via the typical install scripts with Proton.
Because it can be challenging to get net framework installed in wine prefixes even without proton involved, and because of the number of games that require it is huge, there needs to be better support for installing it for proton prefixes.
Risks [optional]
Possibly legal ones depending on implementation.
References [optional]
https://github.com/ValveSoftware/Proton/issues?utf8=✓&q=net+framework
https://github.com/ValveSoftware/Proton/issues/495
And many other as of yet unreported ones (like paladins and smite, killing floor 2 also optionally requires it)