[BUG] viz get stuck at 15% in pivot app

[webcoderz]

if you hit run all pivots, the viz seems to get stuck at 15% loading
so it seems to have uploaded... but then failing viz

steps to reproduce
-- in pivot app, create a new investigation
-- for pivot, can be Enter data with value [{"src_ip": "127.0.0.1"}], rest as defaults
-- hit runall
-- viz uploads, but viz viewing gets stuck at Downloading Arrows and warming GPU session... (15%)