I assume you're not actually sending back 262 photos for a request? If so, cut it down to 1. All you need to know is the album to do anything with it, as you can seek the data you require with just that information.
That doesn't appear to be a PHP error. That looks like a status 500 possibly from an IIS server? These typically occur before the PHP processing starts, but if its IIS I can't be sure as I've never used it with PHP before.