SSL Error 61 on Citrix Access Gateway with Linux Client

I got the Linux client installed in the previous post, but got some SSL errors when trying to launch apps.
Our certificates are issued by Comodo, and the Linux Citrix client didn't support the root server for some reason.

• I used Firefox to view the certificate by clicking on the blue part at the start of the URL.
• Click 'More Information'
• Click 'View certificate'
• Click 'Details'
• Click the Root Certificate at the top of the heirarchy
• Click 'Export'
• Save the certificate as type 'X.509 Certificate DER'
• Save the certificate as 'RootCAName.crt' (Replace RootCAName with actual name)
• Copy the certificate to /opt/Citrix/ICAClient/keystore/cacerts.

I have read that you can copy the CACerts from Firefox, but I haven't tried that.

Thanks to http://www.itswapshop.com/tutorial/how-install-citrix-receiver-linux-120-opensuse-121 for the pointers.