While working a blog I encountered following error when I tried to upload an image.
Warning: trim() expects parameter 1 to be string, array given in /public_html/wp-admin/includes/image.php on line 300
It was strange and once of it’s kind error which you see in WordPress. My first guess was file size, but it was just 30kb image. However the images were added.
Not sure why it happened, so the best solution is to ignore it and carry on.