Numbers 15.4 quits unexpectedly on Mac M3 Ultra
Numbers version 15.4 quits every time unexpectedly on Mac M3 Ultra Tahoe 26.5.1
iMac 27″, macOS 10.15
More detail. Although Numbers 15.4 requires macOS 26.0 or later, it may be happier if you update Tahoe to 26.7.1 and then launch Numbers v15.4 again.
Did you subscribe to Apple Creator Studio or forego that option?
Does it quit before you have an opportunity to open any existing Numbers document, or does it quit opening a specific Numbers document? Quit attempting to open a standard or custom user template?
Does Numbers quit when you are opening an Excel .xlsx spreadsheet in it?
Did you have Numbers v14.* installed prior to installing Numbers v15.0 or later? It may not have copied over your custom Numbers templates. Are these present in the Template Chooser > My Templates?
Once Numbers crashes, it will continue to read its last saved execution state with subsequent launches until you derail that behavior. Press and hold the shift key while launching Numbers to do that.