Unable to generate the derived image located at public

Hi Be_design did you ever work out what was causing this as I have the same problem.

Unable to generate the derived image located at public://styles/large/public/media-youtube/fHF-O2iSv_k.jpg.

I have solved this problem by removing the YouTube video from preview under manage file display.
It seems that if YouTube video is enabled on preview under manage file display then the preview image does not pull through.

You should just have the YouTube preview image selected.
Hope this works for you let me know how it works out.

I'm not positive, but I think that this happens when the original image is very large, say, 4000px. I am running into the same issue. I will update if I find a resolution.

EDIT: Actually, this doesn't seem to be the case. Still digging...

Ok, I found a comment in the API that was helpful to me.

http://api.drupal.org/api/drupal/modules%21image%21image.module/function...

For this function to work, you have to specify the path in the form :

public://name_of_the_image

Not so obvious when you come from D6. I guess it's the case in many other places.

I was passing the complete path, sites/default/files/..., to the function and that was causing it to throw this error.

Any more news on this? When I run it on my wamp setup at home, everything works fine. As soon as I upload to a test server, I get this issue.

Is it happening for a lot of people or just a minority?

Let me add my 10 cents worth of experience here. I have researched this issue for a long time and I found there is confusion created by Drupal. Here is what I have come up with...
It is very important to make sure Drupal knows exactly where your pictures are, including the default picture. If you got an "Error generating picture" message then Drupal could not find it.
At some point, you have declared where your files should be uploaded.
In the user's Account setting page (example.com/admin/config/people/accounts) you have to look at the first two boxes in the PERSONALIZATION section.
The first box is labeled "Picture directory." Enter a sub-directory there, such as "pictures" This is the place where Drupal will go look for your default picture. Put it in this sub-directory and it will coexist with other user pictures that are uploaded by users. Now your declared picture directory is consistent with your previous path declaration.
Now, if your default picture did not show up prior to this it is very likely that you entered an URL or a path (everyone knows the difference between a URL and a path?) in the box below that, the one labeled "Default picture" hoping Drupal would find it somewhere there. And it's not too surprising since under that box it tells you to enter a URL there. But that's wrong, there should be no such path in that box that is in conflict with other paths you have declared elsewhere. So, make sure you enter a sub-directory in the box above that one.
So, what is this second box for then? Well it declares the name of your default picture and allows you to use picture styles (like cropping and resizing.) So, if your default picture is named, say "nophoto.jpg", you must enter a path and the name in the following format: public://pictures/nophoto.jpg
Needless to say: if you have declared a private upload file directory, then replace "public" with "private."
I hope this helps..! :)

This bug seems to be tied to the Styles module. Since #1658102: Remove M:YT support for Styles module, all support for the Styles module has been dropped in favor of file entity's manage file display with view modes. Hopefully anyone with similar problems will benefit from Triumphent's detective work, but as a whole this issue is a won't fix.

Great posts:) In our case this log error was caused by just a simple directory ownership issue.

public://imagefile/path/image.png was owned by username:username so we set the imagefile directory via

sudo chown -R username:nobody imagefile

This error went away:) username:nobody in our case is our host username and nobody is apache2 as set in /usr/local/apache/conf/httpd.conf will show you the apache group user and username by default. More on apache config can be found here http://www.centos.org/docs/4/html/rhel-rg-en-4/s1-apache-config.html

Note: If you have a public://styles directory present chown that username:nobody as well.

This is a correction as the issue is back... :( Drupal can not find the original image it seems. What would be a command via drush to rebuild this. We have used:

drush image-flush

Can we rebuild the image paths anyway?

Watch out for irregular file names (spaces, '&', etc). This has caused problems for many people including myself. I've also read that those chars cause problems some times and not others depending on which browser loads the page first but I haven't experienced that aspect.

Changing public files path resovled the issue for me. replacing "sites/default/files" -> "uploads", removing cache and flush all image styles. Hope it helps!

Just had this problem; looked at files etc.

Eventually found something re image processing; shifted from ImageMagick to GD2 and - hey presto! - the image resising, for Juicebox, worked just fine.
Now hope it keeps working!

I confirm that #14 is the solution, at least for some (in my case, it might be that ALL image styles were not rendered as the generated file did not exist).

My issue arose when I changed the image toolkit from GD2 to ImageMagick (in /admin/config/media/image-toolkit). I just had to revert that and all my thumbnails in the file field, as well as the pictures in my nodes that are inserted with one of the image styles (/admin/config/media/image-styles) are all back.

For the record: I've the same problem: suddenly appearing for SOME users, not for other users with the same role.

Using GD image processing
Tried drush image-flush
Tried rebuilding permissions

OK, solved: when user has access to "Use the media browser" (from Media module) but not to "Media WYSIWYG", then the problem occurs in case the user uses "Mediabrowser" from the WYSIWYG toolbar. Solved by adding this additional access to the user role.

Simply flipping from ImageMagick to GD and back to ImageMagick seemed to do the trick. Something goofy must have gone on when I first installed ImageMagick.