Running BakkesMod.exe with protontricks (protontricks -c "'$HOME/.steam/steam/steamapps/compatdata/252950/pfx/drive_c/Program Files/BakkesMod/BakkesMod.exe'" 252950) might not start BakkesMod when RocketLeague is already running and give this error:
wine client error:0: version mismatch 759/785.
Your wineserver binary was not upgraded correctly,
or you have an older one somewhere in your PATH.
Or maybe the wrong wineserver is still running?
Running
BakkesMod.exewith protontricks (protontricks -c "'$HOME/.steam/steam/steamapps/compatdata/252950/pfx/drive_c/Program Files/BakkesMod/BakkesMod.exe'" 252950) might not start BakkesMod when RocketLeague is already running and give this error: