Try to use Colins tool to make sure it's not your connection: https://3dxchat-status.com/selftest https://3dxchat-status.com/troubleshooting
The tutorial haven't been a thing for a very long time.
If you have UI scale turned on, it might not show the confirmation popup at the bottom of your screen asking if you are sure you really want to divorce.
This happens when loading a avatar file, just put on some other clothes and put the one you want back on and the print will be reset to 0 without clicking through them all
Those codes are what pose you need to use the furniture.
MF-I-II = Male & Female - Foreplay - Pose 2
Sometimes they may say MF-O-IV
O for Oral, A for Anal etc.
Maybe the installer gets blocked by your antivirus (false positive), so it can''t unpack the files ?
Or your permissions is messed up, try running the installer as admin ?