Most problems have a quick fix. Please try these before you start a new discussion.

The game closes right after PLAY (code 3): Windows gives the port too little memory. Press Win + R, type sysdm.cpl, then go to Advanced > Performance Settings > Advanced > Virtual memory > Change, tick "Automatically manage paging file size for all drives" and restart the PC.
Crashes while playing: update to the newest version in the launcher, set Advanced > Two-stage GPU pipeline to "Off (more stable)", close MSI Afterburner, RTSS and other overlays, and update your graphics driver.
Stutter or low FPS: normal for the first minutes after installing or updating (shader cache). Later it usually means the video memory is full: lower the resolution, use FSR Performance and a 60 FPS cap.
Stretched polygons, flickering or a black screen: update to the newest version, then use Advanced > Clear shader cache. On Intel graphics, turn the upscaler off.
30 FPS only, patches missing or co-op broken: the port needs the unmodified 1.09 eboot.bin. Pre-patched "60 fps" eboots and repacks break it.

More answers: FAQ · requirements and setup: install guide

How to ask for help

Start a new discussion in Help & Support, one problem per discussion. The form already asks for everything our helpers need: port version, game version, GPU and driver, CPU/RAM/Windows, what happens, and your BB Report Tool zip (pinned in #help on our Discord).