I try to implement this interesting solution for latexdiff and multiple files. There are other questions regarding missing perl scripts but I cannot relate them or their solutions to my problem (i.e. perl script not found)(perhaps because I am a beginner). However using...
- Win7 (64-bit)
- GitHub (Sourcetree, Git version 1.8.0msysgit.0)
- MikTex 2.9
- ActivePerl version 5.16.2.1602
- cygwin
I receive the following error:

I am a beginner but already checked that Algorithm-diff is installed:
C:\progs\perl\site\lib\Algorithm

Can someone help? I cannot find the path /usr/lib/perl5.... Latexdiff is installed in C:\Program Files\MiKTeX 2.9\scripts\latexdiff. Perl is installed in C:\progs\perlbut the folder lib\perl5is not there.
Update:
Tried to implement this solution for How to change @INC to find Perl modules in non-standard locations by adding C:\progs\perl\site\lib to the new Environment (User) Variables PERL5LIB and PERLLIB. It did work.
C:\tmp\perlrunningC:\tmp\perl\portableshell.batand then runninglatexdifffrom there worked fine – pluke Dec 30 '19 at 11:02latexdiffto the right version of Perl. If you are on Windows usewhere perland on Linux/macOS usewhich perl. If you have multiple versions of perl then you might face some issues. – Foad Feb 10 '20 at 10:23