Rstan based package, winbuilder r-under-devel failure: SyntaxError: break must be inside loop or switch

Has anyone tried to submit an rstan based package for checking on CRAN or winbuilder lately? R-under-devel via winbuilder is giving me the following note, for the ctsem package. I have no idea what it refers to – I chased down the few instances of using the break function in my package and reworked the code to get rid of them, but didn’t help. Any clues, or idea why
this note is so uninformative, would be welcome…

* checking data for non-ASCII characters ... NOTE
  SyntaxError: break must be inside loop or switch
      at :2513

According to the limited help I found so far, that looks like a javascript (or related language) error…

One of the files in the StanHeaders package is corrupted, and is causing issues in some cases. @bgoodri is currently submitting rstan & StanHeaders 2.32, so will be resolved once those are published