_,,,^..^,,,_ said:

Evaluate: System exception - Access Violation ([ScriptClip], line 4)

or

Evaluate: System exception - Access Violation ([ScriptClip], line 4)

the histogram files are not written, too. Can you help me, please?

You might not have write-access to the directory Avisynth is running from.

Try changing "hist1.txt" and "hist2.txt" to something like "C:\<...>\hist1.txt" and "C:\<...>\hist2.txt".

Replace the "<...>" with a directory you know for certain that you can write to as the current user.

Alternatively, you can try running whatever program is executing the script as an administrator.