Internal Server Error

explode(): Passing null to parameter #2 ($string) of type string is deprecated

[app/dbBlogArticles.php:285] 
[app/dbBlogArticles.php:285] explode()
[app/render.php:154] dbBlogArticles->returnRecord()
[lib/base.php:1995] render->artykul()
[lib/base.php:1793] Base->call()
[index.php:25] Base->run()