If the file does not appear in the uploadtemp folder it would have nothing to do with those lines of code as the Flash script places the file there before the uploader.php script is invoked.

Also, the structure of the $_FILES array you show is not what the uploader.php is expecting. In particular, there needs to be a 'filedata' index and there is not, instead you show a 'uploadedFiles' index.

You should review your CGI logs. There have to be errors being reported.

Here is the $_FILES array that is produced on my installation:
`
$_FILES => (

Filedata => ( name => f011.jpg, type => application/octet-stream, tmp_name => /tmp/phpmrM9wk,

error => 0, size => 249512 ),

)
`

I am having the exact same problem as user maxtel above getting the same PHP error message. However, Zenphoto tells me I have PHP 5.2.9.

I'm pretty much a rookie with PHP - could someone help me and speculate on what might be the issue?

Maybe your php installations misses the json extension. Actually we have a replacement for php version without it. Anyway, the fix for you is to upgrade to the recent 1.2.6 release (you are on 1.2.5)