You could try following the instructions here:
Specifically the following near the end:
By default the port of your RM server is 1000 but you may have changed
it so you need to know both the port and the server. Unfortunately if your
correct release management server is unavailable then the client will error
our and close.
In order to work around this you need to change the URL that tells the
Release Management Client to connect to that specifc server and it is
fairly well hidden. You need to head over to the
Microsoft.TeamFoundation.Release.Data.dll.config file and update it
The Release Management team however have created a handy utility that
may make it a little quicker. You can run
ReleaseManagementConsoleAdjustConfigFile.exe and pass in both the
configuration that you want to change and the configuration property along
with the value.
C:Program Files (x86)Microsoft Visual Studio 12.0Release