I've got a weird issue with an uploading to FTP from a network mapped folder after upgrading WinSCP from version 4.3.2 to 5.7.4.
There is a network mapped folder "Q:\folder1\folder2\folder3\folder 4" with files "file1" and "file2" (names are example).
The command like this (executed through a script or manually in a console window):
put "Q:\folder1\folder2\folder3\folder 4" "./path_on_ftp/" -resume
File or folder 'Q:\folder1\folder2\folder3\folder 4\file1' does not exist. A call to an OS function failed
The same errors shows in the log file (without any additional details).
Uploading of the same files and folders from a local drive works flawlessly.
This error didn't occur in 4.3.2.