project can't open after updated 5.1.1

Hey there @Jessexing and @Himiko_bln! Could you let it roll until it crashes and bring back the crash logs? Upgraded projects sometimes suffer from a Niagara system issue, and that might be the case. However, new version so we may need to see the exact error before I can make a workaround. It should be in your projects Saved folder.

Example thread: