Ever since ios 18 beta my message app crashes i get like 10 seconds and then it kicks it back to homescreen already reset my phone did a hard reset erased my phone completely and started over and still same issue
Message app
Your "message app"? Is this an app you've written yourself, or are you talking about the "Messages" app from Apple?
If it's your own app, debug it.
If it's Apple's Messages app, have you tried turning off iMessage? Settings app > Messages > toggle "iMessage" off, then try the app again. If it works, re-enable iMessage.
If that doesn't work, try signing out of iCloud (at the top of the Settings app), and signing back in.