After enabling on Catalan Wikipedia it was apparent that the majority of errors came from a single IP reporting a repeat problem due to the use of several error-throwing setInterval repeat timer. This makes it harder to track down more severe impactful problems as well as prevents us from expanding the error logging to other larger wikis.

The Minerva skin counts errors that occur and was updated to only count up to 5 errors per session. When we did this our error rate halved from roughly 40k a second to 20k a second.

It's suggested that mw-client-error stops tracking more than 5 errors from a single client to avoid this problem.

For context, 63,583 of 66,727 errors on Catalan Wikipedia are coming from a single gadget with this problem.