I don't know why but I have installed the .net desktop runtime installer (6.0.5 x64) through many ways (Including winetricks) and it gives me the same error... is my wine version busted or somthing?
Try reaching out to Lutris support, there’s large community that’s typically very helpful: https://lutris.net/
On the site main site are a link to the forums and the discord. If you prefer IRC, it’s #lutris on irc.libera.chat
Ok so I was having the same problem as you. After following Quinn64's steps, I went to "Configure" on Lutris, to the last tab "system options", scrolled down to "Game execution" and set a new environment variable with key = "DOTNET_ROOT" and value = "C:\Program Files\dotnet" (everything without quotes). Then I saved and it started working. You could try this and see if it helps.