1) Bussiness Manager installtion fails with error:
C:\Program Files (x86)\Parallels\Plesk\admin\bin>billing-integration.exe --command install Error: Invalid parameters: default_widget_template.The 'C:\Program Files (x86)\Parallels\Plesk\billing\scripts\integration.php' utility was failed. All details of the problem has been stored into the 'C:\Program Files(x86)\Parallels\Plesk\billing\lib\billing-libs\Billing\Integration\Cli/integration.php.crash.log'
2) With SSO enabled (on both the main panel and the Customer & Business Manager) I cannot login, the login page just continues to load. From "%plesk_dir%\admin\logs\sso.log":
C:\Program Files (x86)\Parallels\Plesk\sso\htdocs\base\main_handlers.php(25) error_handler] Script error  in C:\Program Files (x86)\Parallels\Plesk\sso\htdocs\lib\pear\Net\Socket.php (147): fsockopen(): SSL: An existing connection was forcibly closed by the remote host
Or error may be like this:
[ERROR][:\Program Files (x86)\Parallels\Plesk\sso\htdocs\base\main_handlers.php(32) error_handler] Script error  in C:\Program Files (x86)\Parallels\Plesk\sso\htdocs\lib\pear\Net\Socket.php (340): fwrite(): send of 390 bytes failed with errno=10054 An existing connection was forcibly closed by the remote host.
Connection to local Business Manager by 127.0.0.1:8443 failed.
If you use Business Manager locally, add binding for the PleskControlPanel site 127.0.0.1:8443. Open IIS->PleskControlPanel->Bindings and add: https 8443 127.0.0.1.