I presume that you are trying to validate the plan through the IFPUV website. I always try to Validate the plan prior to submission however sometimes you can be sat there looking at charts, AIP, SIDS, computer screen for ages and they just do your head in.
If the AIP states a certain routeing then the non availability of it according to this months Route Availability Document is THEIR problem.
Submit the flight plan with AMENDMENTS BY IFPS ACCEPTED in box 18 and you will no doubt get a more direct routeing in the confirmation than would have been expected. If the filed route generates an error then more often than not you will get a manually generated reply.
Just file it and wait for the manual reply