Sometimes PDF user adds password permission to PDF file to prevent it from unauthorized access. To open these files, you must first enter the password. If you don't have password then you cannot open these files. Sometimes a password protected PDF file becomes corrupted & you are unable to open these files. In some cases, When you opened and downloaded these files, it display an error message on screen “file is corrupt or damaged”.
NOTE: If you don't know the password & you want to repair password-protected corrupt PDF File then you must contact the person that created the pdf set password permissions to fix corruption.
You can use following three possible methods to repair corrupt pdf file:
1. First open Adobe Reader. After that try to open the file from the FILE pull-down menu. In some corruption cases, it fixes the error.
2. Right-click on corrupt pdf files and try to "Rename” it. Save in with any other file name. Sometimes, this step fixed the PDF file corruption.
3. In your system if latest version of Adobe Reader is not installed then first installed it & then try to open the file in latest version.
4. You can use Reader inbuilt option to repair corrupt files. Here are all steps:
(Reader) Choose Help > Repair Adobe Reader Installation.
(Acrobat) Choose Help > Repair Acrobat Installation.
5. When all options get failed then third party PDF repair software can help to repair corrupt file. Through these software you can also remove restrictions applied on PDF files. But for this you have to provide the applied password of PDF file.
All above steps will surely help you to repair corrupt PDF File. If you have any question about it, welcome to comment on this post. I will try to solve all your issues as soon as possible!!