Library not loaded: @rpath/FBLPromises.framework/FBLPromises iOS 13.3.1

This issue is specific to iOS 13.3.1 devices with free dev account, i was struggling with it for 4 days and got the solution.

1. Uninstall Pods from your project folder, use terminal:

   sudo gem install cocoapods-deintegrate cocoapods-clean pod deintegrate pod clean rm Podfile

2. Initialize pods again in project, terminal: pod init

3. In Podfile change this line:

   target 'exampleproject' do
     # Comment the next line if you don't want to use dynamic frameworks
       use_frameworks!
   

   to this lines:

   target 'exampleproject' do
     # Comment the next line if you don't want to use dynamic frameworks
     # use_frameworks!
     use_modular_headers!
   

4. Install Pods again in terminal: pod install

5. Open project by file .xcworkspace and do Product > Clean Build Folder (Command+Shift+K)

6. Run and build with free developer account on your iOS 13.3.1 device.

I had the same problem after updating my iPhone to iOS 13.3.1. The fix that has worked for me: In the Podfile remove use_frameworks! and add ,:modular_headers => true after each pod. Close xcode, update pods and rebuild.

My full Podfile looks like this:

target 'HeatingClient' do
  # use_frameworks!

  pod 'RxSwift',:modular_headers => true
  pod 'RxCocoa',:modular_headers => true

end

As was mentioned above:

Apple blocked utilizing external frameworks on free accounts with 13.3.1 upgrade.

So use developer account with active subscription or use static libraries.

Solution for Cocoapods - use use_modular_headers!

You are probably using free developer account. Apple blocked utilizing external frameworks on free accounts with 13.3.1 upgrade. Try downgrading to 13.3 if still possible or buy Apple Developer License.

UPDATE 04/2020: Upgrading to iOS 13.4 and XCode 11.4 currently solves this issue.