Hi,
this is to help people who facing this message when building application in their iOS devices.
Here are steps to solve this problem.
1- Go to the setting in your iphone 2- General 3- Device managment (under VPN)
4- click on Apple Development
5- click on Trust "Apple Development: youremail@email"
6- you will like this message , press Trust
Great! your project will open in your iOS device now. Note: don't forget to set signing setting in your Xcode
