Issue with wp_insert_post and post_content field error Could not update post in the database

Question

I'm having issues creating an import / caching script to be used within a WordPress site. This feed comes from a single text file that is then parsed and returned as an array.

When running through each item from the feed I am using the wp_insert_post function to add in the data (see below):

$post = array(
    'post_title'        => $property['DISPLAY_ADDRESS'],
    'post_name'         => sanitize_title($property['DISPLAY_ADDRESS'] . "-" . $property['AGENT_REF']),
    'post_content'      => $content,
    'post_status'       => 'publish',
    'post_type'         => 'property',
    'page_template'     => 'page-property.php'  
);  

$post_id = wp_insert_post( $post, true );

When I output the $post_id to catch the error I get the below:

WP_Error Object
(
    [errors] => Array
        (
            [db_update_error] => Array
                (
                    [0] => Could not update post in the database
                )

        )

    [error_data] => Array
        (
        )

)

I have tried taking the actual text that is in the $content varilable and adding that straight into the 'post_content' option and that works fine. It is somewhere between my text and it being passed as $content that is causing issues. I have also tried using the 'post_content_filtered' option, which didn't make a difference.

Has anyone had this issue before or know why this error will be triggered? Without the 'post_content' field it works fine.

*** UPDATED ***

The $content variable contains text from the feed. Shown below with some data blanked out as its for a client. Below is an example of $post outputted to show the data.

Array
(
    [post_title] => Example Post Title
    [post_name] => example-post-name
    [post_content] =>  ***£303.33 pcm***    Available 1st July 

Rent includes all utility bills. A self contained room with your own kitchenette and shared bathroom with one other .
A popular location close shops and all main roads . 
    [post_status] => publish
    [post_type] => property
    [page_template] => page-property.php
    [post_content_filtered] => 
)

Answer 1

Today, I was trying to insert an imported data into WordPress. I was using wp_insert_post to insert data, and it threw the following error:

WP_Error Object (
    [errors] => Array
    (
        [db_update_error] => Array
            (
                [0] => Could not update post in the database
            )

    )
    [error_data] => Array
    (
    )
)

My friend said me that I was trying to insert an non-utf8 encoded data, and WordPress uses UTF8 internally.

$post_info['post_content'] = iconv('ISO-8859-1','UTF-8', $post_info['post_content']);