It seems you are using a plugin called “windstyle-multisite-nav-bar-for-wordpress” which is causing the issue. Try disabling it.
Your site gives this error message – Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/content/58/8521658/html/wp-content/plugins/windstyle-multisite-nav-bar-for-wordpress/WindStyle-MultiSite-Nav-Bar.php:1) in /home/content/58/8521658/html/wp-content/plugins/si-captcha-for-wordpress/si-captcha.php on line 1124
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