Fix i found for Rockstar Games Launcher error #6000.87 for GTA5 : r/gtaonline
How to fix rockstar games launcher offline mode error(#6000.87)| Unable to sign in fix |Gta V part 2 - YouTube
Issues logging in and launching GTA V (Epic Games) : r/GTAV
How to fix Error Code #6000.87 and #1000.1 in GTA 5 - GTA 5 Home - Your Source for Everything GTA 5 How to fix Error Code #6000.87 and #1000.1 in GTA 5