Membership product cannot be purchased. Please remove it from your cart.

https://wordpress.org/support/topic/golden-membership-cannot-be-purchased-please-remove-it-from-your-cart/
I found a piece of code which return true always irrespective of whether there is membership product in the cart. Thats why we are unable to purchase membership products.

pmpro-woocommerce addon->includes/functions.php line 48.

/**
 * Search the cart for previously selected membership product
 *
 * @return bool
 */
function pmprowoo_cart_has_membership() {
	
	global $pmprowoo_product_levels;
	$has_membership = false;
	
	$cart_items = is_object( WC()->cart ) ? WC()->cart->get_cart_contents() : array();
	
	foreach ( $cart_items as $cart_item ) {
		$has_membership = $has_membership || in_array( $cart_item['product_id'], array_keys( $pmprowoo_product_levels ) );
	}
	
	return $has_membership;
}

$has_membership = $has_membership always returns true. Please change this. Thank you