Welcome to Julian Kuiters Friday, October 19 2018 @ 09:51 AM AEDT

Cannot install applications because the certificate for www.yyy.com is not valid

iOS 7.1 has changed the security requirements for installing over-the-air (OTA) / enterprise apps to require the .plist file to be delivered over https

Cannot install applications because the certificate for www.example.com is not valid

If you're receiving the above error message when attempting to install your own iOS OTA / enterprise app, you'll need to change the url parameter of the itms-services link to use https. Obviously the location you are delivering the .plist file from will need to be on a website with a secure certificate already installed.

Change the http to https in the &url parameter
itms-services://?action=download-manifest&url=http://example.com/manifest.plist


Changes to:
itms-services://?action=download-manifest&url=https://example.com/manifest.plist

The url's within the .plist file (to the .ipa and images) can still be delivered over http. Its just the .plist itself that must be delivered over SSL.