Certificate Services Support

Affected Devices:
Apple devices running Citrix Receiver version 7.2.2
Includes: iPhones and iPads.

Error:
Connection Error: Engine was not loaded,; You have not chosen to trust "Entrust Root Certification Authority", the issuer of the server's security certificate. Error Number: 183.

Cause:
As part of new security enhancements to the Citrix Receiver clients for the Apple platforms, Receiver for Mac 12.5 and Receiver for iOS 7.2.2 introduces a new, stricter, validation policy for server certificates. 

With this change the Receiver client now uses all certificates supplied by NetScaler Gateway during the SSL certificate validation process. This includes all intermediate and root certificates associated with the server certificate.

In the event that any certificate in the chain is missing, not trusted, or incorrect, the connection fails. This validation policy is stricter than typical web browsers enforce. (Citrix, 2017)
 
Solution(s):

Option (1) Update to version 7.2.3 release June 14th, 2017. This update can be completed via your devices application store. (Liu, 2017)

Option (2) De-link intermediate2.crt and root.crt from the certificate path in NetScaler. (Citrix, 2017) (Stalhood, 2017)

1) From the NetScaler GUI, select NetScaler > SSL > Certificates .
2) Right click on the Root Certificate and select Unlink.
3) Right click on the Intermediate2 Certificate and select Unlink.

References
Citrix. (2017, 02 21). Error: "You have chosen not to trust the certificate” When Using Receiver for Mac 12.5 or Receiver for iOS 7.2.2 or Newer Versions. Retrieved from Citrix.com Support: https://support.citrix.com/article/CTX108800