The best practice to upgrade to newest version is:

1. backup configuration files

(default: c:\Winflector\server\tguicfg) and optionally c:\Winflector\server\guiapp.cfg if exists)

2. backup optionally  license file (if you have activated Winflector version*)

(default: c:\Winflector\server\license)

* - you can always activate your Winflector server online

3. uninstall old Winflector server first and then install new version

4. Now you can copy backup’ed  files to your new installation and run server

The new Winflector version 3.9.4.0d will be released today (5th June 2017).