Windows Messenger 4.7 blocks recipients who send messages to me

Hello,so i have windows messenger 4.7.0105 and when somebody msg me he gets automatcly blocked and when i press unblock it doesnt unblock! it will only unblock if i close the convo window and its then normal but if i say hi to someone and he repys like after 2 minutes he gets blocked and when i press unblock it doesnt unblock! it will only unblock if i close the convo window. here a picture



help?

I have a hunch, as an experiment, go into Options, Privacy tab and set ‘All other users’ to the Allow list. Then try it again.