MLB the Show 23 is an excellent game, so it's rather disappointing when players run into issues. Lately, gamers have been seeing the "unhandled server exception" error message quite frequently, and it has been dissuading them from playing.
Fortunately, this is not a game-breaking error. It's a pain and an annoyance, but it's not going to cost players more than a few minutes of time to try to fix it. Fortunately, there are easy ways to fix this.
Currently, there's no official fix from the developers, but a game update will eventually be released. Those often have bug fixes and take care of any issues. More can pop up later, but the "unhandled server exception" shouldn't.
Troubleshooting tips for MLB the Show Unhandled Server Exception error
Troubleshooting methods are not guaranteed to fix the Show 23. However, they are a good way to alleviate issues for the time being and get players playing their favorite games again.
Try logging in and logging out of your account. Whatever platform you're on has an account attached to it, so log out and in to reset the connection briefly. Resetting the application can be annoying, but it is also a good way to troubleshoot MLB the Show 23 issues.
Since the game does rely on the internet, a strong connection is good. If errors persist, resetting the internet in your space might be worthwhile. Restarting the console and giving it a break is helpful, especially for older consoles.
These aren't going to remove the underlying issues, but they can be a helpful workaround in the meantime.