Unable to see thumbnails of images on the website archives rubrics

I have a multisite installation (WP 3.5.1) based on sub-directories. In the main blog multisite installation is not a problem, but in other blogs do not display thumbnail images in the archives categories.

Displays only the empty box at the post. I tried the image to open this box, but I got only a warning:

“A TimThumb error has occured

The Following Error (s) occured:
Could not find the internal image you specified. “

The article shows photos normally.

On Google, I found an article that the problem would probably be solved, but unfortunately I do not have such experience I was able to integrate code. Can you please anyone advise or recommend a different approach to the thumbnail function normally? Thank you.