Invite User error

I installed akaunting in my own host and i still cannot add new user / invite user and always display "Oops! Something went wrong"

Here's my email service seting:
Protocol: SMTP
Sendmail Path: /usr/sbin/sendmail -bs (default)
SMTP Host: smtp.gmail.com
smtp.gmail.com: 587
SMTP Security: TLS
SMTP Username: [email protected]
SMTP Password: mypassword