If OS is 64 bit, customer need to edit the ctsbll.ini file in the installation folder, then under the "[system]" section, add: osType=win64.
The main issue is Telnet doesn't work with the CTS GUI "IUT automation" feature if this setting is not added.
Possible Errors that could be displayed:
Tcl Evaluate() Failed, The system cannot find the file specified. while executing "exp_spawn telnet $IutAddress " (procedure "ConnectToIut" line 33) invoked from within "ConnectToIut " (procedure "::stc::cts::ospf::TestCONFIG2" line 17) invoked from within "::stc::cts::ospf::TestCONFIG2"