Your version of Safari may be blocking the Citrix Receiver plug-in.
If you use Apple's Safari web browser on your macOS device, Safari may be configured to block new plug-ins like the Citrix Receiver. To resolve, you just need to allow our website to use the Citrix Receiver plug-in in Safari.
1) Go to our HarborCloud Logon Page at https://citrix.ourhostedcloud.com
2) Open the Safari menu the upper-left and choose Preferences...
3) Go to the Websites tab
4) Select the Citrix Receiver under the Plug-ins section
5) Select On to allow the our website to use the Citrix Receiver plug-in
6) Log into HarborCloud and try launching your applications again
If you need any further assistance, submit a request to our support team and we will reach out to you shortly.