@ppamin. Please let me know the following:
- How many files are you trying to list?
- Have you toggled the editor and made sure the shortcode is correct?
- Are there any errors in your PHP error log? If so, please post them.
If you want me to look at it directly, please send me an email with a temporary admin login to your site, and I will log in and check everything. However, you still need to answer the questions I pose above. Thanks.