Thank you for your help.
I run an Enterprise app for an organization. iPod 6th generation iOS 10.3
Expiration of certificate and provisioning profile Due to urgency, I created a provisioning profile that pulled in the new certificate.
I imported the certificate into the app, modified some of the code, built it, and created an ipafile.
The development environment network can communicate with the Internet. When I tested the app, the app started without any problems.
Only a portion of the network in the production environment can communicate with the Internet. When starting the app, the following situation occurred.
・Until you start the app 6-7 times, the screen will be blank and the app will crash. After that the screen will be displayed. ・The app starts, but it takes several tens of seconds to start. ・The app starts immediately without any problems before updating the certificate/provisioning profile.
Communication to the Internet is different between the test environment and the production environment, and only the following connections are open in the production environment.
on your homepage Certificate verification When a user first launches your app on their device, it contacts the Apple OCSP server to verify the distribution certificate. If the certificate is revoked, the app will not start. Your device must be able to connect to ocsp.apple.com to verify certificate status.
ocsp.apple.com 80 TCP iOS, iPadOS, tvOS, macOS certificate verification —
Although there is a description, the above port is not open in the production environment.
Could this have something to do with slow app startup in production?
Please teach me how to solve the cause.