If your Windows workstation has been joined to the Active Directory (AD) domain, there could be some confusion regarding authentication to applications and services. By default, once joined to AD, your workstation will authenticate to AD upon login. If you have installed the Putty+Kerberos package, however, it authenticates to the TerpConnect system via Kerberos authentication, not AD authentication. It's possible for your Putty+Kerberos configuration to inadvertently be switched from Kerberos authentication (correct) to Active Directory authentication (incorrect).
You will know this has happened if you launch Putty and attempt to connect to the TerpConnect system, and you get an error message in your Putty window which says:
GSSAPI error: Unspecified GSS failure. Minor code may provide more information
GSSAPI mech specific error: Server not found in Kerberos database
If this happens, close the Putty session, then:
Once you have completed this change, you should be able to launch Putty and login as normal.