Problems logging in

can anybody help me with this error ?

Warning: The magic method Shapely_Related_Posts::__wakeup() must have public visibility in /customers/7/3/5/perlarsen.dk/httpd.www/wp-content/themes/shapely/inc/class-shapely-related-posts.php on line 89 Warning: Cannot modify header information – headers already sent by (output started at /customers/7/3/5/perlarsen.dk/httpd.www/wp-content/themes/shapely/inc/class-shapely-related-posts.php:89) in /customers/7/3/5/perlarsen.dk/httpd.www/wp-includes/pluggable.php on line 1416 Warning: Cannot modify header information – headers already sent by (output started at /customers/7/3/5/perlarsen.dk/httpd.www/wp-content/themes/shapely/inc/class-shapely-related-posts.php:89) in /customers/7/3/5/perlarsen.dk/httpd.www/wp-includes/pluggable.php on line 1419

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