This bug has been added to the tracker:
https://winscp.net/tracker/1716

Thanks. I'm sending you an email with a development version of WinSCP to the address you have used to register on this forum.

Hello,

Just uploaded a file named "dSSfkjl sdAAlkdslkj fdlskjflkdsjflk sdjflksdjflkdsjflkdjdfdflks.aesctr.enc" without encryption, with no problem.

Laurent

Thanks for trying the new functionality.

Does your remote file system meet the requirements?
https://winscp.net/eng/docs/file_encryption#requirements

Particularly, can you create a file with a name about 60 characters long in the destination folder?

Hello,
Just trying new encryption feature. When I try to upload a file, a get an error message:
"No such file or directory.
Error code: 2
Error message from server: No such file"
I attach log file.
Regards,
Laurent