Hello,

I'm trying to upload files to a new Piwigo 2.9.4 album and trying to upload an image using the web interface. The upload process starts, the progress bar shows some progress (up to about 22%), and then the upload hangs.

In Firefox, the browser console shows:

SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data[Learn More] jquery.min.js:5:15991
TypeError: uploadCategory is null[Learn More] admin.php:495:1

And in Chrome, Developer Tools shows:

Failed to load resource: net::ERR_EMPTY_RESPONSE
admin.php?page=photos_add&album=230:1 Uncaught SyntaxError: Unexpected end of JSON input
    at JSON.parse (<anonymous>)
    at Function.m.parseJSON (jquery.min.js?v2.9.4:5)
    at o.Uploader.Error (admin.php?page=photos_add&album=230:477)
    at o.Uploader.<anonymous> (ojjtjl.js:113)
    at Array.<anonymous> (ojjtjl.js:98)
    at i (ojjtjl.js:98)
    at ojjtjl.js:98
    at Array.<anonymous> (ojjtjl.js:98)
    at i (ojjtjl.js:98)
    at ojjtjl.js:98
admin.php?page=photos_add&album=230:495 Uncaught TypeError: Cannot read property 'id' of null
    at o.Uploader.UploadComplete (admin.php?page=photos_add&album=230:495)
    at o.Uploader.<anonymous> (ojjtjl.js:113)
    at Array.<anonymous> (ojjtjl.js:98)
    at i (ojjtjl.js:98)
    at Object.r [as inSeries] (ojjtjl.js:98)
    at o.Uploader.dispatchEvent (ojjtjl.js:98)
    at o.Uploader.trigger (ojjtjl.js:98)
    at o.Uploader.g (ojjtjl.js:113)
    at ojjtjl.js:113

This is on a hosted LAMP webserver, so I have limited access to the server configuration.

A search has revealed several reports of this behavior, but no solution that I can find.

Piwigo version: 2.9.4
PHP version: 5.6.40
MySQL version: 5.6.41
Piwigo URL: http://