Yeah, older releases are tricky to get to. In Support Center from the Calibre Downloads tab, set version to "Older Versions". (It is to the left of the Filter field, above the list of current versions.)
There are four 2017.4 versions in the extensive list -- they correspond to the first release, two update releases, and the special build for NxDAT. Chances are you want the second update release, 2017.4_35.
No guarantee this clears the error -- as noted, other causes could be duplicate names or a mismatch in macro arguments; those will require the help of the creators of the rule file, who are the only ones who know what is in the encrypted section. (Even Mentor Graphics/Siemens can't decrypt.)
Fingers crossed-
Sam.