Running NotebookLM Enterprise (the vertexaisearch.cloud.google.com flavor).
Since around Aug 31, Discover sources search works fine, but clicking Add on
any discovered source fails every single time โ the add RPC (kqBlec) comes
back with error code 3 (INVALID_ARGUMENT) and nothing gets added to the
notebook.
This hit us in the middle of a customer rollout and we had to roll back on
launch day. The customer assumed it was our integration, so we captured HAR
traces to prove otherwise โ it reproduces identically with and without our
infrastructure in the path:
- 4/4 failures across 2 days, 3 different notebooks, 1-10 sources,
including a brand-new empty notebook
- Direct internet connection, no proxy โ same error
- Everything else in the same session works (search, polling, chat),
only the discovered-source add is broken
- Frontend build boq_cloud-ml-notebooklm-ui_20260823.08 โ suspecting a
regression from the Aug 23 deploy
Filed a bug: https://issuetracker.google.com/issues/555304818
Honestly, this one's been rough โ we've been building a feature around this,
got chewed out by the customer for something that turned out not to be ours,
and spent days proving it. If you've seen anything similar, or know anything
about what's going on, a comment would mean a lot. And if you can repro,
a star on the issue would help everyone affected.