Error 400 in the reserved sandbox

[VinuraDhananjaya]

Hi, I am using the ACI simulator-reserved devnet sandbox. Whenever I try to make a change on the APIC GUI I get an error (eg:- creating a node member); 

Error: 400 - the messaging layer was unable to deliver the stimulus (connection error, Connection refused

I am connecting via the VPN and the connection is working fine. Any help would be appreciated. Thanks

[mjmontero]

Hi,

I'm getting this same error. Anyone has any ideas as to why and how to fix it?

I can navigate the GUI just fine; I just can't make/create any changes