We have a prtg installation with a probe and 5 remote probes with unlimited sensors running since some years.
It worked very well since a couple of weeks ago, where we noticed a deterioration in probe performance in sense that we see a large amount of false positives on every kind of sensors; mostly snmp, ssh sensors, dns resolution....
We see on various sensors a list of errors (for example those here under) that appear and then disappear. Going on the destination of the sensor, for example a cisco switch or a linux host, to see in the logs where the problem is, but everything worked fine.
Examples of error messages/weird behaviour are: - No response (check: firewalls, routing, snmp settings of device, IPs, SNMP version, community, passwords etc) (SNMP error # -2003) (very often) - Access violation at address 00C74E8A in module 'PRTG Probe.exe'. Read of address 00000000 (rare) It's a weird problem because the probe - No response (code: PE002) for dnssensors.
What can we check further to solve this ?