I installed new cryptomator and my file uploaded to Dropbox.
Unfortunately this Win10 PC stop working (hdd out of order).
I use old PC with Win 8.1 and installed old cryptomator 1.4. Which files to download from Dropbox and how to open it now ?
You can’t open a vault of an up to date Cryptomator version with an old 1.4 Cryptomator app.
You have to use an app version that fits your vault version.
If you have that, you must have all vault files local available to the app, to add the vault to your app and open it with your password.
Here is how you add an existing vault to your app:
https://docs.cryptomator.org/en/latest/desktop/adding-vaults/
Is it means that I have to find desktop PC with Windows 10 and install new cryptomator ?
After that I have to download from Dropbox my encrypted file and also file vault.cryptomator ?
Is it all ?
You have to sync the folder that is named after your vault to your local pc, including all its content.
If Dropbox provide a file on demand feature, you can use this too to make the files available for Cryptomator (in case you do not want to actually download the complete vault).
Basically the vault files must be accessible by Cryptomator.