Slightly longer running queries (many inserts, distinct, aggregate, and count) over a few million records regularly "fail" by returning no results "Script executed successfully, but there are no results to show". Rerunning these queries multiple times will eventually return a result.
Mongo 3.2, Mac OS X 10.10, Robomongo 0.9 R10
Don't believe I experience this issue with 0.8.x versions.
Example query that return no result:
Hi @hrgerber! It's known issue, so let me suggest you to check workaround described in the ticket #1106 (comment) (increase shellTimeoutSec value) . I believe this should solve the problem. Please let us know if it works for you.