SFTP Process Flow

Hi,

 I imported the SFTP plug-in from the app market, and while running this, I'm getting an error stating "An error occurred in executing an Activity Class".

Here

i. I have given the FT_coniguration code which  I wrote referring to the documentation.

={ hostname:"eu-central-1.sftpcloud.io",
username:"ef87e78f37c646ca8056eabdce3f86e7",
password:"cjunTmFzmlfuuANjI8Xt2afAzeuJ4mno",
port:22,
timeout:60,
appianexternalKey:"secure-credentials-store"
}

ii. all the declared variable

iii. this is the process model trying to retrieve the files from the server, adding a file, and trying to download the same file. But I'm getting errors at the rach phase of executions.

can you please help me to resolve the errors and make the process model execute?

Thanks in advance.