Populating dropdown error : Could not create search

I am trying to populate values to a dropdown using the search query. Following is the code:Subdivisions ListAll*subdivisionsubdivision`mymainlog` | rex field=_raw max_match=100 "<(\d{4})," | stats values(subdivision) as subDivs | mvexpand subDivs | rename subDivs as SubDivisionList -15mnow But I am getting this error `Could not create search`. But this query is running perfectly fine when executing it as a new search. I am getting almost 40 rows in the search results. But none is getting populated to the dropdown. I had even tried adding `head 5`, in order to limit the number of rows, but of no luck. I am using Splunk version `6.5.4` Please help me out.