We tried to reproduce this, but with no luck, and our logs indicate that you can successfully format citations, so the cause is unlikely to be a block which is affecting some web services' use in Russia.
As Stefan mentioned, it is likely that a restart of the extension will fix this, but also possible that the insertions are failing due to a slow internet connection. If that is the case, the best approach is simply to try again.
You can also try inserting references with our optional sidebar add-on. It uses a different method of communicating with the document, and so may be more reliable for you.