I have the same issue, tried to fix it all day but i keep getting th eUnity crash window everytime it passes the IronGate title at lauch... :/

https://quoramarketing.com/fix-valheim-unity-error-crashing-with-error-unity/

Without much info from your post, I can only suggest generic things for you to try. Could you post some more info about exactly what happens and when the crash occurs? Do you get a specific error code?

Have you been able to create a character? If yes, did you use any special characters in the name? That can cause crashes.

Other things to try:

• Validate the game files.
  
• Update your graphics card drivers (do this directly from the manufacturers website, not via Device Manager).
  
• Update your .NET framework software.
  
• Run the game as Administrator.
  
• Turn off the intro
  1) Right-click the game in your Steam Library and select "Properties".
  2) Select "Set launch options..."
  3) Add the command "-skipintro" (without the quotes) in the box & click OK.
  4) Close the Properties box & launch game
  
• Turn off the Steam Overlay for Valheim
  1) Right-click the game in your Steam Library & select “Properties”
  2) Uncheck “Enable the Steam Overlay while in-game” & click OK
  3) Close the Properties box & launch the game.
  
• If you have VR, make sure you turn off the Desktop Game Theatre for Valheim
  1) Right-click the game in your Steam Library & select “Properties”
  2) Uncheck “Use Desktop Game Theatre while Steam VR is active” & click OK
  3) Close the Properties box & launch the game.
  
  Also, do you have XBOX Games installed? If yes, it could be the XBOX game bar, I had issues with that conflicting with Unity games in the past and just had to make sure I didn't XBOX games running when I tried to play a Unity game.
  
  Hope one of these things helps, if not please post some more info so people reading your post can suggest accurate things for you to try. It’s almost certainly something on your machine, not an actual error the developers can fix.