Conflict with page builder re:image edit

Please could you specify in which of the following circumstances the problem occurs:
1. Image inside post/page added with default editor
2. Image indide post/page added with Page Builder + BSTW
3. Image inside widget added with BSTW (in widgets administration)

1.
It occurs with the image inside a page added with the default editor.

Just tested scenerio 2 and 3 and have same problem

I’m not able to reproduce the issue with the same WP/plugin versions, so I think there could be a conflict with a third plugin or the theme. Please try to disable other plugins and/or temporarily switch to the default WP theme. Also take a look at your browser javascript console and verify if any error is reported there. You may find further info on our FAQ page.

Ok, I disabled all plugins except BSTW and Page Builder.
Problem still exists.

I switched themes and all was fine.

FYI, I am using Nirvana v0.9.9 by Cryout Creations.
Thanks for your help.

I will take up the matter with them, eh?

Yes, the problem should be fixed in Nirvana theme. In particular the problem is Undefined index: content_css in wp-content/themes/nirvana/admin/admin-functions.php.

You need to change this

function nirvana_dynamic_editor_styles($settings){
    $settings['content_css'] .= ",".admin_url('admin-ajax.php') ."/?action=dynamic_styles";
    return $settings;
}

into this

function nirvana_dynamic_editor_styles($settings){
    if ( isset( $settings['content_css'] ) ) {
        $settings['content_css'] .= ",".admin_url('admin-ajax.php') ."/?action=dynamic_styles";
    }
    return $settings;
}

Thanks Marco.
That did it!
You are brilliant!

Much thanks!