If you've recently lost work mid-design — we're sorry. A bug was crashing the editor on most sessions that ran longer than five minutes, right when our auto-save kicked in. The very feature meant to protect your progress was the thing taking it away.
It's fixed.
You can now take all the time you need to perfect your sign. Step away, come back, keep tweaking — the editor will stay open and your work will stay safe. Auto-save runs quietly in the background, exactly the way it always should have.
Thanks to everyone who reported it. If you abandoned a design recently because of this, it's worth another try.