Citrix receiver 12.9.1 Error: you have not chosen to trust thawte premium server CA

Hi Everyone,

I have now having an issue running the Citrix receiver 12.9.1 (latest version ) in Mac OS High Sierra 10.13.4.

every time I am starting to open the desktop, there is an error pop- up saying : you have not chose to trust " Thawte premium server ca" the issuer's of security server certificate. then I have no choice but to quit the transaction.

I tried already to check the certificate in keychain access yet no similar to this for me to enable it to trust.

hope you can help? thanks a lot.