Error message

• Notice: Undefined index: nl in superhero_portfolio_preprocess_node() (line 95 of /data/sites/web/audenaertbvbe/www/sites/all/modules/custom/superhero_framework/modules/superhero_portfolio/superhero_portfolio.module).
• Warning: Invalid argument supplied for foreach() in superhero_portfolio_preprocess_node() (line 96 of /data/sites/web/audenaertbvbe/www/sites/all/modules/custom/superhero_framework/modules/superhero_portfolio/superhero_portfolio.module).