Sonicwall VPN client set-up error - Failed to validate the SSLVPN server

Problem: Before I have to call Sonicwall support I was hoping someone here has run into this. I have 2 Sonicwall NSA 2400 in HA. Both running ROM: 5.0.3.3 Firmware: 5.9.0.7-17o. When I try and connect to the SSL VPN on any windows 8.1 machine I get

"Failed to validate the SSLVPN server, the SSL VPN configuration may be invalid or the server may be running on an old or incompatible firmware!"

According to everything I've read, all of it is up to date and compatible with 8.1. Windows 7 and XP (I know, they're being retired) connect without issue. My android and iPad connect fine. I've uninstallded, re-installed, etc... I really don't want to have to call Sonicwall. Thanks in advance.

Solution: Change: SSLVPN > Server Settings > Check Enable Server Cipher Preference - Change to 3DES or AES256_SHA1