No puedo ver los thumbnails de la extensión News Show Pro GK4

Hola tengo un problema con la extensión News Show Pro GK4 , no puedo ver las imagenes, en el manual me dice:

Create thumbnails:
If enable, it uses PHP GD library to generate thumbnails from article source images, otherwise it will display a resize image (if image element is enable - on image order parameter).
Important! If you have problems on thumbnails generation, you need to insure that cache directory on module have rewrite permissions. So, if this is the case, use your FTP software to access cache directory and change permissions to 755 or higher.
You also might need to check if you have active on your website PHP GD library and which version bundled (2.0.34 compatible). Contact your host provider to provide this requirements.

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