Right after MCS was released yesterday (per SAL)
17:15 <bsitzmann@deploy1001> Started deploy [mobileapps/deploy@b04c397]: Update mobileapps to 3edfcad (T220045 T219411 T219667)
we've seen a sudden increase in the number of errors reported by our edge servers. Upon inspecting the issue this morning, I found that indeed some urls return errors consistently, see for instance
https://fr.wikipedia.org/api/rest_v1/page/media/Nikolai_Gorbachev
this must be fixed ASAP, I am even tempted to do a MCS rollback right now, but I am unsure what that would mean for anything relying on it.