The resource could not be loaded because the App Transport Security policy requires the use of a secure connection

I have solved it with adding some key in info.plist.The steps I followed are:

1. Opened my Project target's info.plist file

2. Added a Key called NSAppTransportSecurity as a Dictionary.

3. Added a Subkey called NSAllowsArbitraryLoads as Boolean and set its value to YES as like following image.

Clean the Project and Now Everything is Running fine as like before.

Ref Link: https://stackoverflow.com/a/32609970

EDIT:OR In source code of info.plist file we can add that:

<key>NSAppTransportSecurity</key>    <dict>        <key>NSAllowsArbitraryLoads</key>        <true/>        <key>NSExceptionDomains</key>        <dict>            <key>yourdomain.com</key>            <dict>                <key>NSIncludesSubdomains</key>                <true/>                <key>NSThirdPartyExceptionRequiresForwardSecrecy</key>                <false/>            </dict>       </dict>  </dict>

Be aware, using NSAllowsArbitraryLoads = true in the project's info.plist allows all connection to any server to be insecure. If you want to make sure only a specific domain is accessible through an insecure connection, try this:

Or, as source code:

<key>NSAppTransportSecurity</key><dict>    <key>NSExceptionDomains</key>    <dict>        <key>domain.com</key>        <dict>            <key>NSExceptionAllowsInsecureHTTPLoads</key>            <true/>            <key>NSIncludesSubdomains</key>            <true/>        </dict>    </dict></dict>

Clean & Build project after editing.

Transport security is provided in iOS 9.0 or later, and in OS X v10.11 and later.

So by default only https calls only allowed in apps. To turn off App Transport Security add following lines in info.plist file...

<key>NSAppTransportSecurity</key>  <dict>    <key>NSAllowsArbitraryLoads</key>    <true/>  </dict>

For more info:
https://developer.apple.com/library/content/documentation/General/Reference/InfoPlistKeyReference/Articles/CocoaKeys.html#//apple_ref/doc/uid/TP40009251-SW33