rescan servers option missing (DC list also missing)...

 

I noticed this on terminals sometimes.   The client will login with the broker ok, but the DC list is completely missing.   Only the option "login" is there.   

But why does this happen?  and how do I get back the rescan servers option along with the list of DC servers.   Even if there is only 1 DC, it should still be listed there.

terminal with DC list showing   terminal with DC list missing

both terminals are on the same computer, just different install folders.  And both terminals are logged into the broker and can perform trade operations.  So why some terminals get like this where the DC list cannot be shown?