The version of assembly (Version=1.3.6.7136, ...; Product: 5.15.0.0) does not exist. You must have some custom build.

Make sure you use the official build of the latest version of the assembly and the same version of WinSCP.exe.

I have recently started having issues downloading files with a script we use. When I first logged into the Client after the issue I noticed the SSH Host Key had changed as I had to accept the new key. Now I can login to the client but when I try to use the script I get an error Authentication failed. I have updated the Key in the script but nothing is working. I also turned on the logging and notice the Key looks different in the client version vs the script version. The client list out the MD5 + the SHA-256 key where the script log only shows the MD5. The version are also different between the client and the automation files I have in the script directory. I tried to update the script automation files but when I did I got "Incompatible external console protocol version 7". I ran the registration command but didn't help.