iOS 26 update prevents access to Messages, Contacts, and Phone app on iPhone

How are you managing your contacts? Are you using iCloud, or another email account? Have you tried a Force Restart on your device? Force restart iPhone - Apple Support

If you open your Contacts app and look in the upper left corner of the screen, if you tap on the arrow there, It should bring you to the Lists page and it should show any and all of the accounts you are using. Make sure you are seeing All Contacts.

You need to provide more information about this. What happens when you try to access any of these apps? What troubleshooting have you tried? What version of iPhone do you have?

Since the iOS 26 update, I'll add a contact, get out of the contacts app, try to locate that contact again, and when I click on it I either get a blank screen or I get info from a previous contact I've searched for prior to them.