I will start by saying that I am a general fan of Sony electronics and gaming, and am extremely disappointed with my xa1 ultra. I bought it brand new yesterday. Will be returning it tomorrow....

As for the specific issue of this thread, my stock messenger app has decided to crash when a specific contact of mine, who also happens to be my most important contact, my fiance, sends me a multimedia message. I cannot say for a certainty it would only be just this one, as I haven't used the phone long enough to start more than 4 total text threads... However the other contacts are able to send photos to me with no issue. 

Here is what is happening exactly:

I receive the notification of a new text, I can open the messenger app, I can click on her profile and open the contact page, and I can even click the thumbnail preview and open the larger preview of the image itself, but I cannot open the actual text/conversation thread. The minute I click on it, it crashes the messenger app and says "messaging has stopped" with a prompt link to restart app.. If I do this, and again attempt to open the message, it crashes again only this time the error says "messaging keeps stopping"  and prompts me to close app. Basically the equivalent of saying to me "oh well you're SOL buddy" very helpful..... 

This happens no matter how I try to access the message thread, whether it be through messaging itself, through the push notifications, or through contacts, etc. Etc. 

I have tried clearing caches and permissions, I have tried launching the OS in safe mode, I have tried force stopping, disabling, deleting permissions for the app and other apps linked with it, reboots, hard reboots, etc etc etc and finally I performed a factory reset and STILL this continues to happen with a fresh factory RESET. everything is up to date and nothing extra has been Installed... 

This is not my only issue with this phone. Or rather, the software itself. I like the phone, the display, the physical properties, but either Android 7.0 is a hot mess, or the Sony custom overlay is to blame... But I suspect a healthy dose of both.... This phone and nougat have both been out for long enough to where this many user interface and app errors are inexcusable. I will be swiftly getting a refund for this phone and staying far away from Sony Mobile for quite some time. 

I was not able to find this specific issue so I wanted to post it so hopefully it can be addressed for the next sorry SOB who comes across it... Or at least put it out there as a known issue...