The ROM has corrupted twice in my recent editing experiences. Other bugs notwithstanding, it's happening because we went ahead and imported events when transferring ROMs even though TF 2.0's event import has an issue handling strings and causes corruption.
We can continue mapping and making events, as the export function works fine. However, we'll wait until the next Temporal Flux release until importing. It's a pretty important one so I'm sure it's at the top of the pecking order.