From the looks of it, I think it's a problem on the server side.
I'm getting the same issue as well.
Thank you for the time...
@Travlr (Main) / @Tymers Realm (Test) 
Sorry if it sounds pissy. It's just that I've been trying on and off for the past couple of weeks to do this (as I want to explore builds and classes without grinding the levels and/or respecing), and literally every time I make an attempt...There's some problem.
The test server is not the right server anymore, when they started testing GR, they moved to the beta server, a new server for testing, and you will now need that client.
MARTy is proof positive the DEVs hate us...
Global: @Reiyichi
Protector (home)
I know this is an old thread, but if the OP is still looking...
Change the file path to:
""C:\City of Heroes\cohupdater.exe" -beta"
Champion/Freedom Servers
@Orion Zidane
@Orion Zidane2
Wrong game version, run patcher and reconnect, server 1850.201007290124.21T2, client 1850.201007290124.28T4
This is the error I get when I try to connect to training room, or training room 1.
Forgive me for being frustrated, but seriously. What the hell?
I've run the patcher multiple times, verified multiple times, outright redownloaded the test client even...and nothing. I haven't been able to access the test server since the last issues I was having with this. Is this common, or am I getting the short end of the stick here?
Should I even bother? Any help would be appreciated here.