The multi-currency mode cannot be enabled as a specific currency was not set. Go to the {bbackup_94402fb9ba80f392e0976ece85f92b2b876bfcaed8d83250cc06083f7139c7d9}1$sWooCommerce settings{bbackup_94402fb9ba80f392e0976ece85f92b2b876bfcaed8d83250cc06083f7139c7d9}2$s page and select the default currency for your store.