Hello,
Were the Best Practices followed before Installing the SEP 12.1 on the Terminal Servers??
Best Practices for Symantec Endpoint Protection on Citrix and Terminal Servers
http://www.symantec.com/docs/TECH91070
Upload us the SEP_Inst.log from %TEMP% folder which would assist us understand the root cause of the issue.
PM me your Case # and Let me check the case.