Ensure you have a valid, signed certificate installed on the appliance. This is a requirement of iOS to allow streaming over HTTPS.
Windows clients are successfully validating your signed certificate, but other platforms (iOS / Android) are displaying certificate trust warnings.
The Foldr appliance is missing the CA Root and/or Intermediate Chain files for your chosen certificate authority. Please reinstall all 4 files (signed certificate, private key, CA root & intermediate chain).
If your provider issues a bundle certificate instead of individual root and chain certificates, install the entire bundle within the ‘Intermediate Chain’ box, leaving the CA Root box blank.
Providing the Foldr appliance is available externally, you can use one of the many SSL validation tools available such as the following to verify your installation: