have you set up IAM Client details? 

Best Regards,

Wasana

It can be IAM setup issue. Please check it first. 

https://docs.ifs.com/techdocs/22r2/070_remote_deploy/400_installation_options/003_security/030_setup_iam_clients/#setup_iam_client_for_ifs_report_designer

Just adding link about certificate handling incase.  

https://docs.ifs.com/techdocs/22r1/070_remote_deploy/400_installation_options/005_operational_reporting/140_install_report_designer/#before_arriving_at_the_customer

I configured the client and downloaded the certificate and placed it in a folder. Unfortunately, the error keeps popping up. I have no idea what next steps to take.

Look at your certificate and see that the issuer is DigiCert Global.  If not, you may have been issued a certificate from your firewall that is doing DPI-SSL.  We had the exact same error and we had to connect to IFS Cloud on a device that wasn’t on our corporate network, download the certificate and install it in the certificate directory of report designer (C:\IFS\IFSReportDesigner\certificates by default).