DISABLE YOUR ANTI-VIRUS OR/AND VPN BEFORE STARTING SC2.
This worked for me. I have my level 175 commander back now.
Before you blame Blizzard, I want to say that my anti-virus and VPN have interfered with other applications in the past, not just Battle.net.
Rule of thumb: when applications or websites act weird, experiment by disabling your anti-virus or/and VPN first.