I don't know if the bug has been fixed or not, but until confirmed otherwise it's safest to assume not. -ArielMT

Feature

Wagn automatically saves drafts of cards as they're being edited, no matter the type, every 20 seconds. This way, if your browser session crashes, you can come back to the card you edited, set the autosaved draft as the current revision, and resume editing from the nearest save to the crash.

Bug

The bug manifests when adding a new card. If there's a lot of time between adding a card and saving its first revision (a great deal, as in a sizeable fraction of an hour), the database may become corrupted. It'll then be impossible to have that card in the wiki. The save will fail, no new card can be added with the failed name, and no card can be renamed to the failed name.

Workaround

Until the bug is confirmed fix, always add content quickly to any new card added, then edit the now-existing card to have the content you intend.