That comes from your Image Slider block. Do you use a custom template?

I'm using the "Business Theme." Do you know how to remove the error?

Thanks

I think I can.

I see that you are using the core SlideShow block on your site (bottomish right on page) and the template used to show that block originally links all images. The template you are using does not but I think you need to comment out one more line of code. This is what you do if you haven't already made an override of the block:

Copy 'view.php' from 'webroot/concrete/blocks/slideshow' to 'webroot/blocks/slideshow/templates/YourTemplateName'. Create the directories as necessary.

Edit the newly copied file (webroot/blocks/slideshow/templates/YourTemplateName/view.php) and comment out line 67 by adding a double slash in the beginning as shown below.

Save the file and close it.
Go to the page(s) or page type using the slideshow block and put the page in Edit mode.
Click on the block and choose Custom Block. Select your newly created template (YourTemplateName above) and exit edit mode.

If I'm not wrong this should fix your problem. If you want to know the innings it will have to wait until tomorrow because it's 35 min 'til midnight and I need my beauty sleep. :D

And, as always, if anyone has a better solution - bring it! :o)