The "ms-xbl-multiplayer" link error occurs when your Windows PC cannot find the correct application to handle Xbox Live multiplayer invites
Then came the 90s, the 2000s, and the cables got lost. The MSX1 and MSX2’s RS-232C serial ports gathered dust. Until now.
Open the Xbox app on your PC. If you don't have it, install it from the Microsoft Store. Click your profile picture and select Support. Choose the Gaming Services Repair Tool.
Arianntape. " You'll need a new app to open this ms-xbl-multiplayer link " I have installed Forza Horizon 4 Hoodlum steam version, Reddit·r/CrackSupport