I have a problem image file names containing utf-8 characters in my drupal website. When drupal has to display a thumbnail (image style) that contains utf-8 characters on it's image file, it fails. All other images/image file names, work ok.
For example there's this image:
The actual image file really exists in default/files/styles/thumbnail/public/ directory, but it cannot be displayed in website.
Visiting the above image url, I can see the following message:
Error generating image.
but I should be able to see the actual image, because it exists on server directory, I can download it using FTP, and it's a normal thumbnail image file.
Why is this happening and what can I do to fix it?