This article describes the issue when EOC fails to poll because Job DLL does not unblock.
Some EOC hotfixes require solarwinds.eoc.jobs.dll to be replaced, and that may cause the file to block. Normally, right-clicking the file and going to properties, then clicking unblock fixes the issue. There are cases where it does not unblock leaving the polling to fail.
Alll versions of EOC
This issue occurs due to Windows file security.