If you can't get to the VSM directly, you could try powering it down then back up, but sounds like a network/firewall issue. 
Dear   I tried to deploy the Eql-VSM ova today. Setup seems to work perfectly, but when I start the vSphere client (5.1), the plugin isn't loaded. Following error is showed: com.dell.EqualLogic Virtual Storage Manager for VMwareDell Inc.3.5.1.169DisabledEqualLogic Virtual Storage ManagerThe following error occured while downloading the script plugin from [URL] The server could not interpret the client's request. (The remote server returned an error: (404) Not Found.) Is this a known issue?
Equallogic VSM (3.5) plugin not loading