You are using an FTP connector with SSL enabled and the following error message is seen when a process is run in test mode.
Test execution of <PROCESS_NAME> completed with errors. Embedded message: IOException caught while copying.
When looking at the process logs, the following message is seen as returned by the FTP Server:
FTP Response for listNames: 450 TLS session of data connection has not resumed or the session does not match the control connection
This occurs when “TLS session resumption” is enabled on the FTP server. Please disable this property on the FTP server and try to connect again.
Additional information available from the User Guide link to the FTP Connector: FTP connection