The easiest is to use the NuGet package:
https://winscp.net/eng/docs/library_install#nuget

Keep in mind that Visual Studio references set the "Copy Local" property to true by default. So, when referencing the WinSCPnet.dll, it will copy it to your bin\output folder and run the DLL from that location. Therefore, the WinSCP.exe file would also need to be in the bin\output folder as well.

Based on your environment and requirements, either copy the WinSCP.exe file to the bin\output or set "Copy Local" to false for the WinSCPnet.dll reference, in which case it will always look in the referenced location for both files.

@KevinCuffe: It's not something to be fixed. You have to accompany WinSCPnet.dll with matching version of WinSCP.exe.
See https://winscp.net/eng/docs/library_install#deploying

Btw, deploying anything to system folders is not a good idea in any case.

And you should upgrade your project to the latest version of WinSCP .NET assembly too. The 5.9.6 is rather old.

Hi, We are getting this is issue when executing transfers via Task Manager since upgrading to the latest versions, however manually transferring files works ok.

01/24/2022 15:00:01 Error: The version of C:\Program Files (x86)\WinSCP\winscp.exe (5.19.5.0) does not match version of this assembly C:\Windows\system32\WinSCPnet.dll (5.9.6.0).

The only way we can get this working again is to re-install 5.9.6.0 which isn't ideal.

Has a fix been found for this yet?

@pradip: Please attach debug log file (Session.DebugLogPath).

Error Message: Cannot use \bin\winscp.exe
Stack Trace: at WinSCP.ExeSessionProcess.CheckVersion(String exePath, FileVersionInfo assemblyVersion)
at WinSCP.ExeSessionProcess..ctor(Session session, Boolean useXmlLog, String additionalArguments)
at WinSCP.Session.Open(SessionOptions sessionOptions)

Thanks. I've improved logging of the issue even more. Please try to reproduce the problem using a build I've just sent to your email address.

Hi Martin,

we updated to WinSCP 5.18.3 RC
I attached 2 log-files.

Thanks. Can you try to upgrade to 5.18.2 beta? It has better logging of issues like this.

Hello Martin,

Thank you very much for your answer.

I am sending you 2 log files attached.

These are from the same system. This morning a file could be uploaded without any problems. This is the log debug-mmg_03032021.log.

An hour later another file should be uploaded. However, this failed due to the known bug. This is the log debug-mft_03032021.log

Nothing has changed during this time.
Just for information: Yesterday 2 uploads could be carried out without any problems.
Maybe you have an idea what else we can do.

Please attach a full debug log file showing the problem (using the latest version of WinSCP).

Since the update to version 5.17.10 we keep getting this error.

'The version of C: \ Program Files (x86) \ WinSCP \ winscp.exe does not match version of this assembly C: \ Program Files (x86) \ WinSCP \ WinSCPnet.dll (5.17.10.0). '

Sometimes it works and the next day it doesn't. It occurs quite arbitrarily.
Both WinSCP.exe and WinSCPnet.DLL are from version 5.17.10

We have completely uninstalled WinSCP. The complete registry cleaned up. Without success.
Before the update to 5.17.10 everything worked without any problems. Unfortunately we were forced to replace the old version 5.5.4.0.

Since it is probably the same error as described above, the question whether there is already a solution? We are grateful for every tip.

@elghali: In your case, this seems to be an XY problem.
Your real problem is discussed here: .Net Core, WinSCP Nuget, Docker on Linux

Is there a resolution for this issue ? thanks

@kiranvm111: Can you send me an email, so I can send you back a debug version of WinSCP to track the problem? Please include a link back to this topic in your email. Also note in this topic that you have sent the email. Thanks.

Are you able to find solution for this.
Please share the resolution

New debug log file is attached

Thanks. I'll send new debug log file as soon as possible

Thanks. I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

Hi martin
Debug log file is attached

Please attach a debug log file (Session.DebugLogPath).

Hi guys

Exception message:

The version of C:\Program Files (x86)\WinSCP\5.17.3.0\WinSCP.exe () does not match version of this assembly F:\MyTask\WinSCPnet.DLL (5.17.3.0).

Stack trace:

WinSCP.ExeSessionProcess.CheckVersion(String exePath, FileVersionInfo assemblyVersion):260
WinSCP.ExeSessionProcess..ctor(Session session, Boolean useXmlLog, String additionalArguments):151
WinSCP.Session.Open(SessionOptions sessionOptions):944
MyTask.Core.FtpClient.get_Session():188

It looks like assembly cannot detect the version of executable file
I've checked both files (exe and dll) and the version for both is 5.17.3.0
I have lots of apps that can work with this exe file at the same time
This error occurs randomly