Situation 1: 
Trying to print out a value in an array. 
Answer 1: 
Try printing out the array. Are you sure it's an array? I've gotten this error when it was an object instead of an array. Try doing a print_r and seeing what you get. 
Situation 2:
You have this associated array like this: 
Array
    (
        [post_id] => 65
        [post_text] => Multiple Images!
        [created_at] => 2014-10-23 09:16:46
        [updated_on] => 
        [post_category] => stdClass Object
            (
                [category_label] => Help Wanted
                [category_code] => help_wanted
            )
        [employee_full_name] => Sam Jones
        [employee_pic] => /images/employee-image-placeholder.png
        [employee_email] => jon@gmail.com
        [post_images] => Array
            (
                [0] => stdClass Object
                    (
                        [image_path] => 9452photo_2.JPG
                    )
                [1] => stdClass Object
                    (
                        [image_path] => 8031photo_3.JPG
                    )
            )
    )
When you try to access post_images array directly within a View, it throws an error. No. Matter. What. You. Do. 
Answer 2: 
Check in all the places where you are calling the View. What happened here is that I was trying to access the same view somewhere else in an area where I wasn't giving the post_images array. Took FOREVER to figure out. 
I hope this helps someone else. :) I just know the error I kept getting didn't help me anywhere.