I was wondering if I can have some assistance, If I goto maps->Layer2 Topology Map and select some devices I get the message ' Unable to get the device connected information from the switch, click  here  to go to the snapshot page.'

On other devices I find I get all the switch connection details. I have checked the SNMP Credentials, MIBs and CLI cedentials and all are ok.

I was wondering if someone can assist me in find out the reason why

Thank you in advance