Upload fails for plain FTP

. 2023-01-20 11:17:28.923 --------------------------------------------------------------------------
. 2023-01-20 11:17:28.923 Using FTP protocol.
. 2023-01-20 11:17:28.923 Doing startup conversation with host.
< 2023-01-20 11:17:28.923 Script: Starting the session...
> 2023-01-20 11:17:28.923 PWD
< 2023-01-20 11:17:28.931 257 "/" is current directory.
. 2023-01-20 11:17:28.931 Getting current directory name.
. 2023-01-20 11:17:28.931 Startup conversation with host finished.
< 2023-01-20 11:17:28.931 Script: Session started.
< 2023-01-20 11:17:28.932 Script: Active session: [1] cpi225001@ftp.vwe.nl
> 2023-01-20 11:17:29.023 Script: pwd
< 2023-01-20 11:17:29.024 Script: /
> 2023-01-20 11:17:29.074 Script: stat -- "/dir"
. 2023-01-20 11:17:29.074 Listing file "/dir".
. 2023-01-20 11:17:29.075 Retrieving file information...
> 2023-01-20 11:17:29.075 MLST /dir
< 2023-01-20 11:17:29.085 250-Listing /dir
< 2023-01-20 11:17:29.085  type=dir;modify=20230120093518; /dir
< 2023-01-20 11:17:29.085 250 End
. 2023-01-20 11:17:29.085  type=dir;modify=20230120093518; /dir
. 2023-01-20 11:17:29.085 Retrieving file information successful
. 2023-01-20 11:17:29.085 dir;D;0;2023-01-20T09:35:18.000Z;4;"" [0];"" [0];---------;0
< 2023-01-20 11:17:29.086 Script: D---------   0                           0 Jan 20 10:35:18 2023 dir
> 2023-01-20 11:17:29.126 Script: put  -nopermissions -nopreservetime -transfer="automatic" -resumesupport="off" -- "D:\Imports\test.txt" "/dir"
. 2023-01-20 11:17:29.127 Copying 1 files/directories to remote directory "/" - total size: 1
. 2023-01-20 11:17:29.127   PrTime: No; PrRO: No; Rght: rw-r--r--; PrR: No (No); FnCs: N; RIC: 0100; Resume: N (102400); CalcS: No; Mask: dir
. 2023-01-20 11:17:29.127   TM: M; ClAr: No; RemEOF: No; RemBOM: No; CPS: 0; NewerOnly: No; EncryptNewFiles: Yes; ExcludeHiddenFiles: No; ExcludeEmptyDirectories: No; InclM: ; ResumeL: 0
. 2023-01-20 11:17:29.127   AscM: *.*html; *.htm; *.txt; *.php; *.php3; *.cgi; *.c; *.cpp; *.h; *.pas; *.bas; *.tex; *.pl; *.js; .htaccess; *.xtml; *.css; *.cfg; *.ini; *.sh; *.xml
. 2023-01-20 11:17:29.127 File: 'D:\Imports\test.txt' [2023-01-19T14:04:56.546Z] [1]
. 2023-01-20 11:17:29.128 Copying "D:\Imports\test.txt" to remote directory started.
. 2023-01-20 11:17:29.128 Ascii transfer mode selected.
. 2023-01-20 11:17:29.129 Starting upload of D:\Imports\test.txt
> 2023-01-20 11:17:29.129 TYPE A
< 2023-01-20 11:17:29.137 200 Type set to A
> 2023-01-20 11:17:29.137 PASV
< 2023-01-20 11:17:29.144 227 Entering Passive Mode (80,85,160,204,12,241)
> 2023-01-20 11:17:29.145 STOR dir
. 2023-01-20 11:17:29.145 Connecting to 80.85.160.204:3313 ...
< 2023-01-20 11:17:29.160 550 Filename invalid
. 2023-01-20 11:17:29.160 Copying files to remote side failed.
* 2023-01-20 11:17:29.160 (ExtException) **Copying files to remote side failed.**
* 2023-01-20 11:17:29.161 Filename invalid
. 2023-01-20 11:17:29.161 Asking user:
. 2023-01-20 11:17:29.161 Error transferring file 'D:\Imports\test.txt'. ("Copying files to remote side failed.","Filename invalid")
< 2023-01-20 11:17:29.161 Script: Error transferring file 'D:\Imports\test.txt'.
< 2023-01-20 11:17:29.161 Script: Copying files to remote side failed.
 
< 2023-01-20 11:17:29.161 Filename invalid
. 2023-01-20 11:17:29.163 Answer: Abort
* 2023-01-20 11:17:29.164 (ESkipFile) Error transferring file 'D:\Imports\test.txt'.
* 2023-01-20 11:17:29.164 Copying files to remote side failed.
* 2023-01-20 11:17:29.164 Filename invalid
. 2023-01-20 11:17:29.164 Copying finished: Transferred: 0, Elapsed: 0:00:00, CPS: 0/s
. 2023-01-20 11:17:29.164 Script: Failed
> 2023-01-20 11:17:29.177 Script: exit
. 2023-01-20 11:17:29.177 Script: Exit code: 1
. 2023-01-20 11:17:29.178 Disconnected from server

public static SqlString Upload(string transferProtocol, string HostName, Int32 Port, string User, string Password, string SshHostKeyFingerprint, string SourceFileName, string DestPath, string SshPrivateKeyPath, string PrivateKeyPassphrase)
{
    SourceFileName = Environment.ExpandEnvironmentVariables(SourceFileName);
    DestPath = Environment.ExpandEnvironmentVariables(DestPath);
    var protocol = transferProtocol.ToLower() == "ftp" ? Protocol.Ftp : Protocol.Sftp;
    var sourcePath = Path.GetDirectoryName(SourceFileName);
    var logName = Path.Combine(sourcePath, string.Format("Log_{0}_{1}.log", HostName, DateTime.Now.ToString("yyyyMMddHHmmss")));
 
    var sessionOptions = GetSessionOptions(HostName, Port, User, Password, SshHostKeyFingerprint, SshPrivateKeyPath, PrivateKeyPassphrase, protocol);
 
    using (Session session = new Session())
    {
        session.SessionLogPath = logName;
 
        session.Open(sessionOptions);
        if (!session.FileExists(DestPath))
        {
            session.CreateDirectory(DestPath);
        }
 
        var transferOptions = new TransferOptions
        {
            TransferMode = TransferMode.Binary ,
            PreserveTimestamp = false
        };
        transferOptions.ResumeSupport.State = TransferResumeSupportState.Off;
        var transferResult = session.PutFiles(Path.GetFullPath(SourceFileName), DestPath, false, transferOptions);
 
        if (!transferResult.IsSuccess)
        {
            return (string.Format("Error:Transfer failed for {0} to {1}: {2}", SourceFileName, HostName, transferResult.Failures[0].Message));
        }
    }
    File.Delete(logName);
    return (string.Format("{0} is uploaded to {1}{2}", SourceFileName, HostName, DestPath));
}

. 2023-01-20 11:32:27.791 Size of 1 local files/folders calculated as 0
. 2023-01-20 11:32:27.834 Copying 1 files/directories to remote directory "/KVKBestand/" - total size: 0
. 2023-01-20 11:32:27.834   PrTime: Yes; PrRO: No; Rght: rw-r--r--; PrR: No (No); FnCs: N; RIC: 0100; Resume: S (102400); CalcS: Yes; Mask: *.*
. 2023-01-20 11:32:27.834   TM: B; ClAr: No; RemEOF: No; RemBOM: No; CPS: 0; NewerOnly: No; EncryptNewFiles: Yes; ExcludeHiddenFiles: No; ExcludeEmptyDirectories: No; InclM: ; ResumeL: 0
. 2023-01-20 11:32:27.834   AscM: *.*html; *.htm; *.txt; *.php; *.php3; *.cgi; *.c; *.cpp; *.h; *.pas; *.bas; *.tex; *.pl; *.js; .htaccess; *.xtml; *.css; *.cfg; *.ini; *.sh; *.xml
. 2023-01-20 11:32:27.835 File: 'C:\Users\adminlangras\Desktop\text.txt' [2023-01-20T10:31:55.351Z] [0]
. 2023-01-20 11:32:27.835 Copying "C:\Users\adminlangras\Desktop\text.txt" to remote directory started.
. 2023-01-20 11:32:27.836 Binary transfer mode selected.
. 2023-01-20 11:32:27.836 Starting upload of C:\Users\adminlangras\Desktop\text.txt
> 2023-01-20 11:32:27.836 TYPE I
< 2023-01-20 11:32:27.842 200 Type set to I
> 2023-01-20 11:32:27.842 PASV
< 2023-01-20 11:32:27.851 227 Entering Passive Mode (80,85,160,204,12,254)
> 2023-01-20 11:32:27.851 STOR text.txt
. 2023-01-20 11:32:27.851 Connecting to 80.85.160.204:3326 ...
< 2023-01-20 11:32:27.864 150 Opening data channel for file upload to server of "/KVKBestand/text.txt"
< 2023-01-20 11:32:27.870 226 Successfully transferred "/KVKBestand/text.txt"
> 2023-01-20 11:32:27.870 MFMT 20230120103155 text.txt
< 2023-01-20 11:32:27.877 213 modify=20230120103155; /KVKBestand/text.txt
. 2023-01-20 11:32:27.877 Upload successful
. 2023-01-20 11:32:27.877 Got reply 1 to the command 4
. 2023-01-20 11:32:27.877 Transfer done: 'C:\Users\adminlangras\Desktop\text.txt' => '/KVKBestand/text.txt' [0]
. 2023-01-20 11:32:27.877 Copying finished: Transferred: 0, Elapsed: 0:00:00, CPS: 0/s
. 2023-01-20 11:32:27.877 Retrieving directory listing...
> 2023-01-20 11:32:27.877 TYPE A
< 2023-01-20 11:32:27.884 200 Type set to A
> 2023-01-20 11:32:27.885 PASV
< 2023-01-20 11:32:27.891 227 Entering Passive Mode (80,85,160,204,12,232)
> 2023-01-20 11:32:27.891 MLSD
. 2023-01-20 11:32:27.891 Connecting to 80.85.160.204:3304 ...
. 2023-01-20 11:32:27.904 type=file;modify=20230120103155;size=0; text.txt
. 2023-01-20 11:32:27.904 Data connection closed
< 2023-01-20 11:32:27.904 150 Opening data channel for directory listing of "/KVKBestand"
< 2023-01-20 11:32:27.904 226 Successfully transferred "/KVKBestand"
. 2023-01-20 11:32:27.904 Directory listing successful
. 2023-01-20 11:32:27.904 Got reply 1 to the command 2
. 2023-01-20 11:32:27.904 ..;D;0;1899-12-30T01:00:00.000Z;0;"" [0];"" [0];---------;0
. 2023-01-20 11:32:27.904 text.txt;-;0;2023-01-20T10:31:55.000Z;4;"" [0];"" [0];---------;0

session.PutFileToDirectory(Path.GetFullPath(SourceFileName), DestPath, false, transferOptions);