What if my computer dies

If its moved, the just reconnect the vault by using the “ad existing vault” function. Means: just tell cryptomator where your vault is located now. Means: it should not be moved anywhere the PC doesnt have access to (obviously).

If you have a backup of your vault (as part of your local backup routine, or maybe it is still anywhere stored online), then just copy the vault to your local storage ans also ad it as new vault.
Please note: cryptomator is not a backup solution.

To keep it simple: as long as you are able to copy/moveback/restore your vault files (anything in the directory where the masterkey file is stored), you can open this vault with the corresponding cryptomator version. “Corresponding” means that for example you cannot open a Version 1.5 Vault with a Version 1.4.x Cryptomator App. Vice versa it is possible as cryptomator will ask you to upgrade your vault.