Avalanche: Why does my Avalanche respond to ping but I cannot connect with the GUI?

Knowledge Base - FAQ

Avalanche: Why does my Avalanche respond to ping but I cannot connect with the GUI?
Often this is caused by a mismatch in the software running on the appliance vs. the GUI.  please ensure that both are the same revision. Also, in some cases we have seen where a reboot of the appliance has addressed this issue.