I receive a blank pg after upload with no error. The url in the browser is the site/zenphoto folder/zp-core/zp-extensions/uploader_http/uploader.php. I have checked file attributes and syntax errors. Any suggestions as to where to look would be appreciated. Thanks

Did you check file/folder permissions and the error logs?

I had checked folder permissions.
I accidentally deleted error logs thinking I was deleting the contents. I haven't found a way of installing them back. The files do upload.

The Zenphoto error logs are re-created once something happens to be logged. You should also look at your server error logs. If you don't know where please ask your host.