Everything in my map disappeared except for the brushwork some of my props were missing before it said that 4 props were missing so i quit and went back in but then everything was gone in my map
Did you get a dialog box asking if you wanted to re-save the map with invalid solids removed? If you click yes, sometimes a bug will obliterate all the props in your map. It's stupid but that's 20-year old software for you. In the future, remove invalid solids by hand by locating them with Alt+P and deleting them.
If this is your first time logging in after the migration (Feb 8, 2022), you must reset your password to log in. Follow this guide if you're having trouble