I installed the search module as normal on DNN 5.6.2 and recieved the following error 
 
Did you install the latest version of our component Aricie.Shared (get it free in download area) ?
Did your portal run the scheduled indexing task before you try to search content or did you run indexing manually before ?
Hi,
you need to configure first the search field in your result settings (Section Querying Settings)
Best regards,
I am also getting this error.  Indexing has occurred both manually and automatically.  I have 1.5.7 Shared installed, 1.4.1 Search installed on 5.6.1 DNN.
The Search Fields as cgaspard mentioned to set is completely blank and won't let me choose any options.
Hi Jason,
When LS is registered in your web.config file, you have to select modules you want to index in the indexer settings
Check a least one module and save it.
After that, you need to re-index your site via menu Host > Search Admin. You can now return in the result settings, search fields will be displayed.
Best Regards,