Same issue. Updated plugin to 3.8, WSOD on dashboard. WordPress email notification indicated Widget Options was causing an error. Had to use recovery mode to disable the addon.
Plugin could not be activated because it triggered a fatal error.
`Warning: require_once(/public_html/wp-content/plugins/widget-options/includes/widgets/option-tabs/days-dates.php): failed to open stream: No such file or directory in /public_html/wp-content/plugins/widget-options/plugin.php on line 202