[TYPO3] No thumbnails in BE

[Christian Lerrahn]

Hi Dmitry,
> Christian Lerrahn wrote:
> > this might be trivial but I still don't really know what the problem
> > is. When editors use content elements that involve images on one of
> > my TYPO3 sites, they will never see thumbnails. Now, I've had the
> > problem before that the thumbnails could not be generated due to
> > configuration problems. However, for one I remember a placeholder
> > showing up in that situation and then I also can't find any
> > configuration errors when I check.
> > 
> > Any other hints what could be going wrong or how to debug this?
> 
> Install tool. There you need to set path to ImageMagick. There are
> also tests there that you can use to check if thumbnails are working.

There are slight problems (mainly different file sizes and one wrong
background colour) in the image processing tests but nothing that would
explain why no thumbnails show up at all. IM is obviously accessible and
working (in principle at least).
I've also tried switching between GIF and PNG thumbnails but it doesn't
seem to make any difference.

Cheers,
Christian