SSLVPN client Not working on PC's

Hi,

I have configure a Sonicewall N3600 with SonicOS Enhanced 6.2.6.0-20n firmware, I created users and assign rights as appropriate, I configure sslvp.

Whenever i try to connect to the vpn on PC with windows 7, 10 or windows server 2012, the get the "error verifying user... incorrect user/password"

I downloaded sonicwall mobile connect on my andriod from google playstore, configure it and all the users are connecting to the vpn.

My question here is, why can i connect from PC's yet i can connect from mobile?

Please help me, this has linger for 2 weeks and i am getting frustrated while my boss is expecting it to work before the end of the week.