What have you tried?
What do the buffers look like?
Which FTP node did you use? (exact name please node-red-contrib-???)
What device and OS are you running NR on?
What version of NR and Node.js (you can get this from the startup log.
Please provide a copy of your flow?
In order to make code readable and usable it is necessary to surround your code with three backticks (also known as a left quote or backquote ```)
```
code goes here
```
You can edit and correct your post by clicking the pencil 
icon.
See this post for more details - How to share code or flow json
