Hi,
In your ACL configuration, you added the group "guest".
A guest user is in the group "guest" in Joomla 3.
Regards,
PS : I recommend you to check the backend_default.css file, I have the impression that this file does not have write permission and was not replaced during the update, you still got the "2.0.0" file.
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.