I hope, that the developers of the AFDKO read this message, too.
It is not needed to command FinishInstallWindows.cmd, if you command ttx.cmd directly from the directory "Fdk/Tools/Win".
But, there is a bug. I am using AFDKO version 2.5 62754. Maybe that is the same bug as in version 2.5 61250:
As a workaround you can change the following line in ttx.cmd from
%AFDKO_Python% %AFDKO_SCRIPTS%\ttx %*
%AFDKO_Python% %AFDKO_SCRIPTS%\ttx.py %*
Note, that "%AFDKO_Python% %AFDKO_SCRIPTS%\ttx %*" was not a bug in former versions!
I think, that there is the file "ttx" (without extension) missing in the directory
Now (change number 62754) there is only ttx.py in that directory.
The content of "ttx" in "Tools\SharedData\FDKScripts" was:
#! /usr/bin/env python
from encodings import latin_1, utf_8, utf_16_be
from fontTools import ttx
I have a request to Adobe: Please make the older change numbers of AFDKO 2.5 available, because it is easier to locate those bugs then. Sometimes you create new bugs, while you are fixing bugs.
Quoting a line from the release notes of FDK v2.5 April 5 2014 change number 61944 (!)
Fixed FDK/Tools/win/ttx.cmd file so that the 'ttx' command works again.