I use MySQL Community Edition and I solved this problem today.
- goto https://dev.mysql.com/downloads/mysql/
- download the ZIP archive of your desired version
- Open the ZIP archive and go to "bin" folder
- extract MYSQLDUMP.EXE where you want
- Close the Zip Archive and open MySQl Workbench
- In MySql Workbench goto to Edit > Preferences > Administration
- Select the file that you just extracted in "Path to mysqldumptool"
- Press OK and it's done!