What are these 'Last 25 Events'

Hello,

so I'm always getting Events like this:

„DHCP Scope: (Voice Vlan 66.. 1) and Lease: 172.28.12.60 overlaps in the range(s) : (172.28.12.1 - 172.28.13.239)“

But i don't understand what that means, how can the address 172.28.12.60 overlap the range 172.28.12.1 - .239 ????

Same goes for events like this, what does this mean:

"DHCP Scope: IFX-WIN-Server-Auto, IFX-WIN-Server-Auto overlaps in the range(s): (172.28.16.7 - 172.28.16.16) "

I clicked help, and there it says "Clicking the event description opens the corresponding Orion NPM device Details page ....... " but I can't click anything at all, no page with more details that would explain the issue opens.