gRPC-Core.modulemapでmissing module map fileというエラーが表示される(Swift)

Question

Archiveをしようとした所、次のエラーが発生しました。

Build target gRPC-Core of project Pods with configuration Debug
error: missing module map file: '/Users/名前/Dropbox/Swift/SomeApp/Pods/Target Support Files/gRPC-Core/gRPC-Core.modulemap (in target 'gRPC-Core' from project 'Pods')

以前にはこの様なエラーもなく、Itunesconnectの審査も通っておりました。
pod updateやpod installをしましたが、ターミナルには以下のように表示されました。

Errno::ENOENT - No such file or directory @ rb_sysopen - /Users/名前/Documents/Swift/SomeApp/Pods/gRPC-Core/include/grpc/module.modulemap
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:904:in `read'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:904:in `read'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:904:in `block in create_module_map'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/user_interface.rb:145:in `message'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:903:in `create_module_map'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:68:in `block in install!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/user_interface.rb:145:in `message'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:34:in `install!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator.rb:114:in `block in install_pod_targets'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator.rb:111:in `map'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator.rb:111:in `install_pod_targets'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/single_pods_project_generator.rb:32:in `block in install_all_pod_targets'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/user_interface.rb:145:in `message'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/single_pods_project_generator.rb:31:in `install_all_pod_targets'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/single_pods_project_generator.rb:19:in `generate!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:308:in `block in create_and_save_projects'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/user_interface.rb:64:in `section'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:303:in `create_and_save_projects'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:295:in `generate_pods_project'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:174:in `integrate'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:162:in `install!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/command/update.rb:63:in `run'
/Library/Ruby/Gems/2.6.0/gems/claide-1.0.3/lib/claide/command.rb:334:in `run'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/command.rb:52:in `run'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/bin/pod:55:in `<top (required)>'
/usr/local/bin/pod:23:in `load'
/usr/local/bin/pod:23:in `<main>'

どの様にすれば解決できるのかご教示願います。