This post is to help others who have the same issues as well as a reminder to myself if this ever happens again.
Basically I was downloading some files from my server using filezilla via ssh when this error occurs “critical file transfer error” . Really I thought what gives? See the image below.
Apparently this happened because I was downloading 2 directories with the same name but different casing. The source server is a Linux server while my machine is Windows. The problem is that Linux file system is case sensitive while Windows is not! This caused errors.
As an example, if the Linux server has 2 directories “Puppy” and “puppy”, when downloaded into Windows, only the first one is created. Weird things happens when the cration of the second directory is attempted.
In any case, all I did to solve this was to delete one of the directory in my windows machine.