we have a PRTG installation with about 400 Sensors and until two weeks ago everything went fine. Now at random intervals the sensors suddenly start changing states from OK to Warning to Error and back. I can't pinpoint any patterns neither in kind of the sensors nor in what part of the network they are in. The system- and sensor-logs seem fine in that regard. I have increased the scanning interval to 5 minutes which remedied open requests going above 100 but it doesn't change anything regarding the status-changes. I hope you can help me. If you need any additional information I'll be glad to provide.