5.9. The 'r' command isn't inserting the file into the text.

On most versions of sed (but not all), the 'r' (read) and 'w' (write) commands must be followed by exactly one space, then the filename, and then terminated by a newline. Any additional characters before or after the filename are interpreted as part of the filename. Thus

       /RE/r  insert.me

will would try to locate a file called ' insert.me' (note the leading space!). If the file was not found, most versions of sed say nothing, not even an error message.

When sed scripts are used on the command line, every 'r' and 'w' must be the last command in that part of the script. Thus,

       sed -e '/regex/{r insert.file;d;}' source         # will fail
       sed -e '/regex/{r insert.file' -e 'd;}' source    # will succeed