Just saw this. If it says max sessions, go to Home Page - Buddy Auth Portal and login with whatever login you created to buy DB, go to "Sessions" and check the tickbox next to your key and "kill" that session. Then you can log in as normal. Mine does it after I have to restart it a few times, due to the crashing.
Can't help you with the crashing, I'm still waiting on an answer to my own freezing/crashing thread. Hope that helps with max sessions though.
remove: - microsoft .net framework 4 client profile - microsoft .net framework 4 extended - microsoft visual c++ 2010 x86 redistributable - microsoft visual c++ 2012 x86 redistributable
restart your pc, download the installationwizard from https://www.thebuddyforum.com/BuddyWizard.exe run it as administrator. after the wizard is done, run windows update. And install all updates for .net & c++ restart