Why can't I connect SSL VPN to USG FLEX H using SecuExtender SSL VPN Client Windows client 4.0.5.0?

Zyxel_Emily

Question:
Why can't I connect SSL VPN to USG FLEX H using SecuExtender SSL VPN Client Windows client 4.0.5.0?

Answer:
The old SecuExtender SSL VPN Client Windows client 4.0.5.0 is not compatible with USG FLEX H series.
https://download.zyxel.com/SecuExtender_VPN_Client/software/SecuExtender%20VPN%20Client_SSL_VPN_Client_4.0.5.0_2.pdf

To resolve this issue, please switch to the IPSec_SSL_VPN_7.7.50.008 (subscription-based) Windows client. This client is compatible with your USG FLEX 100H and should allow you to establish a secure connection without any difficulties.