Either of the following results can occur:
Unable to Save and assign the search is returned. 
2. When attempting to save the search with no options checked, the search does not save and no error is returned.
The issue is caused when more than 1000 characters are entered into a single search field.
Each search field should be limited to 1000 characters or less.
When attempting to save a search within a Case the search may not save or will return an error when trying to Create Review Set.