I tried to detect the device via snmp in Open-AudIT 2.0.4 but unfortunately it failed.
In previous versions 1.12.10 gun correctly.
Thank you for your support. Unfortunately, it did not help. Increasing the Discovery Log to 7 shows nothing.
Additionally, in order to check how it works I installed virtual appliance. Version 1.12.10 works much better.
There is a possibility the permissions on NMAP may have been overwritten during the upgrade. Please follow this procedure: https://community.opmantek.com/display/OA/Open-AudIT+FAQ#Open-AudITFAQ-Discoveryhasstoppedworking
If that does not address you problem, set your log_level to 7, run a discovery on an individual device, then open that Device's Details page and check that device's Discovery Log for details.