Hi,
there is a conflict with plugin "Art Sexy Lightbox", this happen because Custom SQL Where trigger content plugin to replace sql code with out Content Plugin, this is useful if you want to put a query to have users with equal values (for example users near you, users with same interests or users with same value in some custom fields).

Anyway normally each content plugin have a code to not trigger with com_finder indexing.

Solutions:
1. If you do not need this plugin you can disable it.
2. Try (read note1) to add following code (read note2) in file /plugins/content/artsexylightbox/artsexylightbox.php before line 32

if ($context == 'com_finder.indexer')

		{

			return true;

		}

note1: I can't try this with "Phoca Commander", because it is dangerous, if something not works and this break also Joomla backend I can't revert original file (you can try this fix with FTP)
note2: We also recommend to contact developer to fix this, this cause breaks and/or performance issues in Joomla com_finder.