Many users have been experiencing errors uploading CLs to Gerrit. Currently tracked as
https://crbug.com/1103153 (unfortunately restricted viewing due to debugging trace information) and
http://b/160761155. The Gerrit team has been actively working to mitigate and the situation should already be getting better.
We believe the same issue is causing high error rates for code search when attempting to fetch files from git to show them.
I'll update this thread, and remove the banners showing up in Gerrit, when the problem is confirmed to be fully resolved.
Andy