I am on shaky ground here as I really need Steve (Mr Papa) involved in this one as I have not had anything to do with the coding of this plugin.

But – having said that – a search through the code shows this message to be coming from the plupload javascript runtime and is caused by an http error being returned. So – somewhere along the line your server is not liking things but I am unsure what!

I would start off my reducing the permissions on the upload folders from 777 to 775. Some hosts do have triggers that will stop writing to the disk if the folder is 777. I would also perhaps check the /tmp folder which can cause problems if it is full.

And Steve will be along later so we can get him involved.

0777 would not be the best permission…  should be 0755 but not likely the issue…

that is an internal plupload (the 3rd party app we use for uploading) error message…  not really sure why you are getting it – its never cropped up before…  Nor can I find any information on it at the plupload site…

can you verify that your php.ini does set up a tmp location for file uploads? normally is /tmp on servers…

anything unique about this file? how large?

This is incredibly odd head scratcher, but I think I might have figured out what’s going on.

After logging into my forums (as admin), I proceeded to upload a 2 files: an image and a text file

The above is what I see. It says that test-1.txt file uploaded properly, and Airplane1.jpg didn’t.

Out of curiosity I decide to check out the contents of the upload folders, and to my surprise it’s been uploaded! 

At this point, I turn on the error console on Chrome and retry the process. This is the error I get:

Now I’ve no idea what this means.

I’ve even uninstalled a the plupload plugin and reinstalled it.

Any advise? 

A ‘500 Internal Server Error’ really needs to be taken up with your host company. I would send then this image and explain what was going on when it happened. It might come down to simple server configuration. Either way it needs to be looked at by the hosting.

I would ask them at the same time if it is possible that mod_security is installed on the serve and could this be the culprit. Also point out to them that this was an ajax call.

We would be interested in the response.

Ok I figured it out and fixed it. I’m on a VPS where I setup LAMP. I did however forget one small crucial part,

I forgot to install php-gd. Once I got that installed, everything worked perfectly!

odd…  the php gd library should not be needed… will have to consult with the plupload folks…

but good find!

I think it needs PHP-GD because PLUpload uses:

function imagecreatefromjpeg() in /plupload/library/sp-plupload-components.php

and from http://php.net/manual/en/function.imagecreatefromjpeg.php

Note: JPEG support is only available if PHP was compiled against GD-1.8 or later

Yes – that is my understanding as well.
I realise yours was a local install bit I believe that it is most rare these days for a hosting php install not to include gd.

yeah, I found the same this weekend when working with plupload…  just didnt know it before…