Creating a new certificate and then immediately adding it to your mac, using either xcode or manual download and addition to the keychain, results in the certificate being presented as expired in project settings/Platforms/iOS/mobile provision. The certificate continues to be presented as expired for two hours, after which it is no longer presented as expired.
I’m guessing that it is somehow the editor running on mac that causes evaluating the timing of the certificate in a faulty manner, as the certificate is valid in both the key chain on mac and in the editor on PC.
It should be easy enough to recreate the issue by making a new certificate and import it in the editor immediately after.
Yes. I did it both through xcode and the developer portal. I did it three times. The first two out of confusion as to why the certificate started out as expired, and the last to confirm that it had to do with passing of time after the second one had turned valid.
I did not realize you were in Denmark. So this is an issue with localization and can take anywhere from 1 to 24 hours before your Certifications and Provisions will appear as valid, depending on your time zone. If you currently cannot wait until they become valid, you can use the workaround described in the link you provided above.
However, I agree that this is less than ideal and have entered a bug report to correct this: UE-37298. You will be able to track the status of this report on the following link: Unreal Engine Issues