Having trouble activating WooCommerce Subscriptions on your site because activation of the extension crashes your site completely? Look at your error message (if you have none, activate WordPress debug mode) If your error messages includes a failed call for get_editable_roles
then we got you covered.
Download this patched file (fixed by Gabor Javorszky, thanks!), courtesy of Prospress and replace your includes/admin/class-wc-subscriptions-admin.php.
This should solve the issue.