I believe this original issue is separate to the new iOS 13.3.1 issue that is going around. This new issue, one that I have myself seems specific to those with a non-paid developer account and the apps can load onto the simulator but not onto the iPhone itself.You can reference https://forums.developer.apple.com/message/404653#404653 and see if any of the solutions there help. If not, still waiting on a resolution from Apple.

I know a lot of people that are also looking to roll back due to the issues that 13.3.1 has caused for Apple developers with free accounts. The update has now prevented them from installing their apps on their devices for testing. I got lucky and managed to get it done withing the window, however this is still only a temperary fix. I don't know if 13.4 will fix this issue.I really believe that Apple should have left the signing window open longer due to this issue.

Unfortuantely commenting out 'use_frameworks!' or/and adding 'use_modular_headings!' does not work for me.It fixes the errors while creating other errors.The only temperary fix that I have found is rolling back to 13.3 and this has its own complications.This has been extremely frustrating, and not that I would mind paying for the developer program but for my project and purposes I am not allowed to pay for anything.

Yes, I am having the exact same issue after updating to 13.3.1 and was no longer able to deploy my app to my device. When I went to verify that I should be able to as a developer with a free account, I see it states it clearly on Apple's website that it says I should. https://developer.apple.com/support/compare-memberships/ Under the 'Who Should Enroll' title it states "You can learn how to develop apps for Apple platforms for free without enrolling. With just an Apple ID, you can access Xcode, software downloads, documentation, sample code, forums, and Feedback Assistant, and you can test your apps on devices."Whether this is a bug or issue, I am trying to find out. I am hoping that Apple have not revoked this ability as it it essential for my project.The only workaround that I have just found and do have some undesirable side effect are to roll back to iOS 13.3. By doing this I was then able to deploy my app to my iPhone however I was unable to restore my backup without it requiring to update. Most things on my phone have their own backup and most of iCloud data stays intact however you have to reinstall everything.