Thanks for using EasyRotator for WordPress and sorry for any inconvenience! This is usually due to conflicts with different versions of the Shortcode Ultimate plugin. Please try the following simple fix:
1. Select Plugins > Editor on the left menu in the dashboard
2. On the upper-right, note the "Select plugin to edit" menu. Select "EasyRotator for WordPress" from the list and click Select.
3. On the list of files on the right, click "easyrotator-for-wordpress/compatibility.php"
4. In the main editor area, scroll down to the bottom of the code
5. You'll see the code you should comment out by adding
(the code to comment is shown here: http://i.imgur.com/iuwGJ0L.png)
Please let me know if I may provide any additional assistance.