First, try another rerun (the EU will do one rerun automatically). This could be a simple transitory server-side fail. There is another post (different tool) that seems related. See below.
There could also be an input problem. There is much discussion at this forum about the tool. I added a tag to your post that will find most of it.
Shortlist of checks – details for these and more in other topics:
Are the inputs green datasets that actually contain content?
Does the ID type/format match the parameter settings?
If all seems ok, please post back a 1) screenshot of the tool form (rerun icon will bring up the original run), the 2) expanded input dataset in the history panel, and a 3) sample of data (top of the file is best – click on the eye icon).