Fundraising: PayPal not working

PayPal sandbox isn't working when used with Fundraising plugin, the page gets redirected to plugins checkout page when an user is trying to back a project.

    Ivan

    Hi Lucas Guedes !

    I noticed some problems in the plugin. I fixed theirs on your site and ping our developers to include these changes to the new version of the plugin. If you have the same issue on other sites - you can make these changes:
    Open {wordpress_folder}/wp-content/plugins/fundraising/fundraiser.php file via FTP and replace this line in create_error function (approximately 1228th line)
    $content = 'return $content."<div class=\"'. $classes.'\"><p>' . $msg . '</p></div>";';
    to
    $content = 'return $content."<div class=\"'. $classes.'\"><p>' . esc_html( $msg ). '</p></div>";';
    It adds ability to see the errors from Paypal.
    Also, open {wordpress_folder}/wp-content/plugins/fundraising/lib/gateways/paypal.php file and replace this line in process_advanced function (approximately 215th line)
    $nvpstr .= "&displayMaxTotalAmount=TRUE";
    to
    $nvpstr .= "&displayMaxTotalAmount=true";

    Best regards,
    Ivan.