On iOS devices, we receive the error profile installation failed while trying to install the Second profile.

Verify whether the MDM server is Load balanced. Ideally this may come across when the server is in Load balance with SSL Offload.
Verify whether the CAcert is present on the Web Tier. Needed to copy/import the cert and run the following commands.
Web Tier does SSL Offload and App Tier uses SSL Bridge

Executed these commands on Tier1 Web NS and bind to 443 LB
 
-add ssl action insert-certTag -clientCert ENABLED -certHeader NSClientCert
-add ssl policy insert-certTag -rule CLIENT.SSL.CLIENT_CERT.EXISTS -action insert-certTag
-bind ssl vserver  XDM-443-OL -policyName insert-certTag -priority 1
-set ssl vserver XDM-443-OL –clientauth enabled –clientcert optional
-save config

Alternatively you could do the same from the NS GUI as well.

Note : Please take a backup of the Netscaler policies prior to making the changes.