Gen 8.6 script "%GEN86%\Gen\REGTE.CMD" Parm (parameter) #3 "Location of TE Service executables" references this Visual Studio 2015 sub-directory which does not exist:
set service_path=%GEN86%\Gen\VS140\
Release : 8.6
Component : Gen Transaction Enabler
The reference to '\VS140' is an error.
For Parm #3 use "%GEN86%GEN" or "%GEN86%GEN\amd64" for either the 32bit or 64bit TE to be registered. That will override the incorrect default value of set service_path.
This problem has been fixed in post Gen 8.6 Complete PTF RTN86201/SO10992