New Site throwing an Error Message

We are using WinSCP Version 5.6.1(Build 4547) on our remote server.
We are attempting to add a New Site and Save it and when we do so, we get the following error message...

No argument for format 'System Error. Code: %d.%s%s'

We did Google the error message and saw a post to check the Language Preference and it is indeed English...actually the only language available.

We were successful in saving the New Site on our local WinSCP.

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