I recently got this error in Visual Studio for Mac when setting everything up for iOS development:
Failed to synchronize email@example.com account with Apple Developer Portal. “Failed to resolve forward links for Apple Developer Portal client. Reason: Please check your internet connection or try again later.”
After receiving it, I did the usual process of checking my developer account, confirming I’ve accepted any new terms and conditions and making sure I am part of the team that develops the app. However, all these things were correct.
Eventually, after giving up the fight with Visual Studio, I decided to try to add my details into Xcode, seeing as Visual Studio uses it as part of the build process. I added my Apple account in Xcode -> Preferences -> Account. This worked, and then next I clicked the “Download Manual Profiles” button.
Once the profiles had been downloaded, I opened Visual Studio again and this time it worked. 🎉