Why Yandex XML began to issue The desired combination of words is not found anywhere?

Question

API

I purchased limits on Yandex XML and yesterday I made a script that worked properly
This morning all of a sudden all Yandex XML requests began to answer "The desired combination of words is not found anywhere"
I have a lot of limits, IP did not change, I tried different requests but everywhere the same , although yesterday it worked on the same requests.
Why is that?

Answer 1

the limits
are not always obvious - you can think that you are doing "everything is pa-chasnam", but alas,
well, there is a small chance that something is wrong with them , although again -
well, or you ask for limits not according to your sites