After upgrading ASA IOS to version 9.14.x the Remote Access VPN Connection failed.

After checking debug logs and config the cause was located as Authorisation server LDAP over SSL connections failing.

Before the upgrade LDAP over SSL connections were working fine. The new version of the software was failing as the certificate used by the LDAP server (AD CA) was not trusted by the ASA.

This was fixed by exporting the AD CA certificate from the Windows server and importing it into the ASA (under Configuration -> Remote Access VPN -> Certificate Management -> CA Certificates).