> Please set debug-on-error and byte-compile-debug to t to try and get
> a backtrace for it.

Attached.

But please see my other replies, where I acknowledge that my code does call
`byte-compile'.  See the question there about whether byte-compiling a Lisp file
also compiles a sexp (e.g. a defun) inside `eval-after-load' (and if so whether
that is true in older Emacs versions also).