Update

How do you send an error log?

at the bottom of the screen in samsung members you'll see the different page options in my screenshot below. you want to select support on the far right then once on the support page scroll down to find quick help and select feedback. when you open feedback your logs will begin being sent. it is very important to send your logs via that feedback option within 15 minutes of the error that occured. you'll want to keep samsung members open until you receive the notification that the log submission was completed before closing the app. it can take several minutes for your logs to be sent to the backend team as well so don't panic if it feels like its taking forever 🙂 Its always a good idea to include any screenshots and a detailed description of what happened when any error happened on your end. that also helps samsungs teams to narrow down the issue to fix it.

So you can check the status of the report once its been sent however generally a response won't be sent back unless they need more information from you. And from looking at the message your device experiencing a severe crash. Did the phone randomly reboot while you were using it? From the look of it if you were actually looking at the screen when it happened you would have had a frozen screen then watched it reboot showing the samsung knox logo as if you had just restarted your device. As long as you sent your logs thats the magic sauce to help the backend team correct whatever caused the crash. Its definitely scary seeing that message though but you didnt do anything wrong. Have you noticed anything else since this happened? And did all of your other apps and google play updates go through without a hitch as well?

The stylus isn't working as well but no issues and nope didn't reboot.

since this all happened and your device didnt reboot on its own, have you restarted your device? I saw where you said you had already ran the diagnostics on your device and nothing was showing any errors or that they weren't working at that time. However with the S pen now not working see if you can run the diag on just the s pen. To run just the one test when you go to diagnostics and it begins all of them tap back one to bring up the full menu of tests and just select the S pen. This is quite the pickle you have going on with different functions simultaneously not working.
Another thing to check is both google play and the galaxy store to insure you don't have any other updates that didn't complete on their own once you updated to One UI 9. Lastly in your settings menu go to your google services. once on google services scroll down until you see system services and select that option. If you see any updates in system services that need to be completed go ahead and push those through as well. sometimes not everything gets with the program accordingly. I've included a screenshot for reference of what you'll be looking at in system services.
Restart your device once you complete any remaining updates if it does not automatically prompt you to do that.

Diagnostics working on this during last hour
No answer yet.

I want to get rid of function. No help at all.

What model device are you using? And Did your finger print scanner stop working after updating to One UI 9?

Thats good news. This most definitely points to a hiccup in the software though. Just don't attempt a roll back or clearing any data. Generally fixes for something of this nature are sent out rather quick. Samsung's teams have been working hard on these roll outs to all of our devices one by one. I couldn't imagine what its like for their employees during major OS rolls outs and unpacked events lol the only appropriate background music during such wild events would be under pressure by queen and david Bowie 😆

Is your device having any other issues since this happened or was it a one off?

as long as the error log reports are being sent through the proper support que immediately following the error & toast message then that will definitely samsungs development team get to the bottom of what is happening. I can assure you this not intended behavior of the software. Also what device model did your error happen on? Was it immediately following the One UI 9 update?