MCP Server not working in Figma Desktop

I had the same issue. At my end it was caused by a Windows port rule I added myself.
After running the netsh command in admin mode MCP in Figma was reachable again.
Claude code found this out btw...
 

Found the culprit. There's a Windows port proxy rule:                            
                                                                                   
  Listen: 0.0.0.0:3845  →  Connect: 127.0.0.1:3845                                 
                                                                                   
  This is the issue. The portproxy is binding to all interfaces including          
  localhost, which means when Figma tries to start its own MCP server on           
  127.0.0.1:3845, the port is already taken. That's why you can't toggle MCP in    
  Figma anymore.                                                                   
                                                                                   
  To reverse it, you need to run this in an elevated PowerShell or cmd on Windows  
  (as Administrator):                                                              
                                                                                   
  netsh interface portproxy delete v4tov4 listenport=3845 listenaddress=0.0.0.0

  Or I can try running it from WSL — but it typically requires admin rights. Want
  me to try, or do you prefer to run it yourself in Windows?

  Also note: removing the portproxy will break the Figma MCP connection from WSL
  (since that's what the rule was for). After Figma can toggle again, there's a
  better approach using listenaddress=172.31.96.1 instead of 0.0.0.0, which would
  only expose the port on the WSL gateway interface rather than on localhost.