i install the last version of piwigo.
in upload tab when i want to authorize categories to allow user to upload the photos,the authorized block is empty.
why the categories dont show in this block????
I suppose you're talking about screen [Administration > Categories > Properties > Upload].
I guess it's because you only have virtual categories and no physical categories. The user upload form in Piwigo 2.1 requires a physical category for upload. To create a physical category, read instructions on [Administration > Photos > Add > FTP + Synchronization].
Another way to offer upload to your members without giving them administration status is to use [extension by plg] Community and give a link to download pLoader to your upload granted users.