– Blank page in the frontend, where the slider is published.
– Blank page in the backend at the Smart Slider.
If somewhere the Smart Slider would cause a blank page, in the backend or the frontend, then you should go to System (in Joomla 2.5: Site) → Global Configuration.
Go to the Server tab and pick Maximum at the Error Reporting.
Then go to the page, which was blank, and now it should write out an error, or more, but probably only one of them is the real error, which is causing the other ones. These are usually server side configuration issues, like the php is missing a basic library, or the memory limit is too low, and your server host can help you with that.
If this wouldn’t write out anything, then you could try to make your website write out the error by opening up this file:
for frontend: /modules/mod_smartslider2/mod_smartslider2.php
for backend: /libraries/nextend/joomla.php
Write this into the beginning, right under the <?php part: