error code 4 when I try to upload a file via sftp about dartssh2 HOT 5 OPEN

Dart Version 2.16.1
Flutter Version: 2.10.1

I will attach the corresponding exception

flutter: SftpStatusError: Failure(code 4)
flutter: SftpStatusError: Failure(code 4)
flutter: #0      SftpClient.open (package:dartssh2/src/sftp/sftp_client.dart:63:5)
<asynchronous suspension>

from dartssh2.

The OpenSSH SFTP server use 'Failure' message for many errors and it's hard to tell the specific reason. This usually happens when the permissions is not enough, or the filesystem is read-only.
Does your account have enough permission to write to the remote destination?

from dartssh2.

Hey, thank you very much for quick answer!
permission is granted, I also tried out the admin user of the server. Do you have another idea?

from dartssh2.

Currently I have no other ideas about the error. However it may help to inspect the logs from sftp-server and see what actually happened. Detailed instructions can be found here: https://access.redhat.com/articles/1374633.

from dartssh2.

Thanks for the help @xtyxtyx . I don't get any specific error message.

It seems like the session closes immidiately.

Mar  6 18:35:01 xxxxxxx CRON[2024678]: pam_unix(cron:session): session opened for user root by (uid=0)
Mar  6 18:35:01 xxxxxxx CRON[2024678]: pam_unix(cron:session): session closed for user root

Do you have any idea?

from dartssh2.