I'm having the same issue and also I see some reference to what seems to be Windows C: drive. Maybe the tool only runs on Windows for now.
Microsoft.PowerPlatform.Dataverse.MCP
Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.
at PowerPlatformMCPProxy.ConnectionManagement.UrlConnectionExtractor.ExtractUrlConnectionDetails() in C:\__w\1\s\src\MCPServers\PowerPlatformMCPProxy\Clients\UrlConnectionExtractor.cs:line 22
at PowerPlatformMCPProxy.Runtime.MCPServerProxy.RunAsync() in C:\__w\1\s\src\MCPServers\PowerPlatformMCPProxy\Runtime\MCPServerProxy.cs:line 58
at Program.<Main>$(String[] args) in C:\__w\1\s\src\MCPServers\PowerPlatformMCPProxy\Program.cs:line 35
at Program.<Main>(String[] args)
zsh: abort Microsoft.PowerPlatform.Dataverse.MCP