Trying to answer Using Bash/Perl to modify files based on each file\'s name I ended in a point in which I don\'t know how to use find and sed all t
find
sed
I really think the issue is that your files name contains a / that is why sed believes it start the options strings.
/
Replace / by @ in you sed command would do the job.
@
I try that on Linux BASH and it work perfectly
find . -type f -exec sed -i -e "s@text@test plus {}@g" {} \;