I've been seeing this in the overnight runs of the browser tests in recent times. The build for VisualEditor will fail with a modal dialog that says "Error loading data from server: readonly. The wiki is currently in read-only mode. Would you like to retry?"
Here is an example from the overnight run Sunday 18 May: https://wmf.ci.cloudbees.com/job/VisualEditor-en.wikipedia.beta.wmflabs.org-linux-chrome/512/testReport/(root)/VisualEditor/Edit_with_strings__outline_example_____Editing_with_%C3%84%C3%8B%C3%8F%C3%96%C3%9C___Editing_with_%C3%84%C3%8B%C3%8F%C3%96%C3%9C___/
I can't think of any reason why beta labs would be in read-only mode late on a Sunday (PDT).
I suspect this may also be the cause of the occasional failure in other builds with less information, for example "too many connection resets (due to Net::ReadTimeout - Net::ReadTimeout)" that we see in the MobileFrontend builds: too many connection resets (due to Net::ReadTimeout - Net::ReadTimeout) https://wmf.ci.cloudbees.com/job/MobileFrontend-en.m.wikipedia.beta.wmflabs.org-linux-firefox/571/testReport/(root)/Check%20UI%20components/Check_existence_of_important_UI_components_on_other_pages_/
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=68349
