Short description of Zip Repair Tool 3.3: If instead of zip files you find a message saying " Cannot open file: it does not appear to be a valid archive" , it means that the files are damaged and stand in need of zip repair. To fix the problem, open the files in Zip Repair Tool. The program features a sophisticated recovery algorithm that restores zip structure integrity and helps recover zip files with their contents. You can easily repair zip files of any size and number of volumes.