This fix made by Aggravating-Sky8697.
I made this guide with their permission.

The fix should significantly reduce crashes by over 90%+. Note that it works well only for Intel+NVIDIA PCs at this moment.

To help author make improvements and give them feedback and logs, please contact them on their Github[github.com].

The instructions are easy:

1. Go to author's Github[github.com]
   
2. Download "Magicka.Fixes.V1.X.zip"
   
3. Extract files from archive directly to game's folder and replace default files

Fix v1.4 was released on 01/05/2024.

List of fixes of latest patch release (V1.4):

• Fixing out-of-memory crashes and timeout issues in the netcode.
  
  
  • Added LARGEADDRESSAWARE flag to the PE header to enable 64-bit address space.
    
  • This change will address most out-of-memory errors that everyone has been experiencing.
  
  
• Multiplayer Cutscene Timeout:
  
  
  • In multiplayer, if a client wants to watch a cutscene lasting over 60 seconds, the host will kick the player due to timeouts, thereby ending the game.
    
  • Increased the timeout to 120 seconds.

You can find full list of fixed on the Github page.

MagickaFix on Github[github.com]. Please use Github to contact author and leave your feedback!

Author's post on Reddit. Give them some karma :)

VirusTotal for modified Magicka.exe:

• 1[www.virustotal.com]
  
• 2[www.virustotal.com]
  
• 3[www.virustotal.com]
  
• 4[www.virustotal.com]

Guide icon created by Icongeek26 from Flaticon[www.flaticon.com].

Этот же гайд на русском.