If I were to hazard a guess, it looks like something is misconfigured, like an IP is included in your IP range that either isn't configured, or isn't supposed to be monitored. One thing you may want to do is set up so that only 1 protocol is being used, WS-MAN or Redfish. 

Do all of the target servers have OMSA installed on them?

Thanks for the reply.

Servers are running ESXi so they are managed using WS-MAN (out-of-band).

I can't see any configuration options to use REDFISH in OME (only WS-MAN out-of-band option is selected).

We are seeing this now too. It's just one server, but every night at the same time we get this error. It's in the same discovery pool as a dozen other servers, not sure what could be different, or why it only happens on that server at that time. Looking at the logs OME has been able to log in without issue on every other attempt.

As it turned out warnings were caused by incorrectly configured credentials in Configuration Inventory Schedule.

Manage > Configuration > Configuration Inventory Schedule

Hope that helps.

That was it, inventory schedule had the wrong credentials. Strange, I don't remember setting it up!

Thanks!

Hello,

I have the same issue but I presume that Manage > Configuration > Configuration Inventory Schedule is from old OME version. Now we have 3.9 and I can't see anyway to change credentials for Inventory Schedule. Once I do onboarding that's the only place where I put credentials. Is there any other place where put credentials? Or is there any other solution to this case?

Hello

this guide can help you

DDell EMC OpenManage Enterprise 3.9 User's Guide | Dell US

• In order to support discovery with domain credentials, OpenManage Enterprise (version 3.2 and later) uses the OpenSSH protocol instead of the WSMAN protocol used in the previous versions. Hence, all the Windows and Hyper-V devices discovered prior to updating the appliance have to be deleted and re-discovered using their OpenSSH credentials. Refer the Microsoft documentation to enable OpenSSH on Windows and Hyper-V.