Would you check ?

FileZip "C:\\test.txt.zip", "C:\\test.txt"
--> OK

FileUnzip "C:\\test.txt.zip", "C:\\test.txt"
--> not work

The second parameter must be a destination directory name, not a name of file you want to unzip.

FileUnzip "C:\\test.txt.zip", "C:\\"
--> OK

: Would you check ?

: FileZip "C:\\test.txt.zip", "C:\\test.txt"
: --> OK

: FileUnzip "C:\\test.txt.zip", "C:\\test.txt"
: --> not work