Azure websites ftp upload fails on some files but not others

This sounds like a time-out issue on the server. You will need to tell your FTP client to keep the connection alive so that it doesn't start a second connection while the first connection is still trying to upload the files.

To set this in FileZilla client, go to Edit, Settings, Connection, FTP, and check "Send FTP keep-alive commands" checkbox.

For more detailed explanation of the problem, visit: http://blogs.msdn.com/b/wats/archive/2013/12/13/setting-up-a-passive-ftp-server-in-windows-azure-vm.aspx Scroll towards the bottom and read the "Points to consider from Azure SLB perspective" section.

I had the same problem with my FTP on Azure and checking the "Send FTP keep-alive commands" checkbox above solved my problem.

Hope this helps!

I was having the same issue with Azure + FileZilla. I solved the problem by connecting to the FTP host name and not the FTPS host name.

I ran into a similar issue, but with a slightly different error message:

Response:   150 Opening BINARY mode data connection.Response:   550 The supplied message is incomplete. The signature was not verified. Error:  File transfer failed

I solved the problem by using CuteFTP instead of FileZilla.