Unable to use key file "C:/putty/calrsa.ppk" (unable to open

I have a putty ppk file that works in the graphical version of WinSCP but when I try to use it in a script I get the error Unable to use key file "C:/putty/calrsa.ppk" (unable to open file)
Why would the scripting version not be able to use the same file that the graphical version is using?
winscp version is 5.5.5

I'd guess that it's because the forward slashes in the path. You need to use backslashes in Windows path.

I'm having a similar problem. The C# application is trying to access the ppk file using the ftp login as the network credentials. How do I keep this from happening?

jdiaz wrote:

The C# application is trying to access the ppk file using the ftp login as the network credentials.

I do not understand, what you mean by that.