Your machine has no TLS 1.2 support, i don’t know how to get the ProxHTTPS thing, but it can be fixed by enabling TLS 1.2. You need to install a specific update from POSready 2009, and then enable with a registry tweak.
Client is unpatched, there might be an underlying network issue, or a generic incorrect password/email, or if on XP and Vista: SSL/TLS error due to incompatibility.
So as mentioned above by lucascg02, it could be an SSL issue, though I’d be sure to make sure your client is properly patched – I would check that first, and if you haven’t, use our new patcher.
I was having the same problem with MSN Messenger 7.5 on XP, which before worked despite having to try to login after 3 times or more, until it stopped for good with error 80048820.
I solved the problem with the help of a friend, who gave me the hint to open a registry file by enabling POSReady 2009 and then installing the windowsxp-kb4019276-x86-embedded update file and then restarting Windows. After that, MSN 7.5 came on the first time! It works for Messenger 8.1 and 2009, but you also need to enable TSL 1.2 in the registry and that’s it, you don’t even need to use the proxy.
PS.: There are two files and I will leave them here. XP needs to be up to date or at least have the latest updates.