Why is an atypical response returned when calling notifications.sendMass?

Question

Classmates

For a long time, there were no problems using the notifications.SendMass method.
The last use returned an atypical response: "t11447251416020000_133_s"
Notifications were not delivered.
The app has been running for over a year.
We send the following parameters to the API:

format=JSON&gender=MALE&expires=2015.11.15+14:00&application_key=APP_KEY&text=TEXT&method=notifications.sendMass&sig=SIG

Answer 1

We are now changing the work of game notifications somewhat, in connection with this, the id format has changed somewhat.
Also, during the transition, there may be significant delays in the delivery of notifications to users, we will try to reflect the current state on the Platform Status page .