Problem on uploading a file using ftp (Filezilla) ---> wkhtmltopdf 43,5 MB

I got the problem that everytime I do an uploading of all _lib files the procedure stuked on trying to copy from local to server the (incredible crazy…big file) from the following directory…
_lib/prod/third/wkhtmltopdf/osx/Contents/MacOS/wkhtmltopdf

Filezilla continue to try to copy it but everytime stopped and restart once again.

I did a workaround renaming the file wkhtmltopdf into wkhtmltopdf.aaa . Once copied I rename it back to wkhtmltopdf.
I don’t know why but it works.

Are there someone who knows how to avoid this invented workaround ?
Thanks