Uploading file to our site, in some cases you may see the error message: “Unsupported file format or file is not password protected.” We have been often asked why such an error may appear even for a valid document protected with a password. So we decided to write an article, answering the question, to save some time, both yours and ours.
And it's not a software crash or a problem with your file. The fact is that even seemingly identical files may have different internal structure. For example, a *.xlsx file may be a document of MS Office 2007, 2010, 2013 or later versions. Mind, that each Office version has a completely unique format and algorithm for password protecting. Even within one Office version file formats of two documents may be drastically different.
The same information applies to other formats. Same-looking *.pdf files may be created by Adobe Acrobat of any version: starting from version 2 and ending with 11 or later, and each Acrobat version has its own unique password protection algorithm. The internal structure of a PDF file also depends on the chose variant of file protection: it may be a password for opening, or the protection from performing certain operations (copying, printing, commenting, etc.). Similar problems may occur in processing other types of files.
At the moment, we have some problems with processing the following file formats:
- MS Office documents with password protection from editing. We handle only those files that have password protection from opening the document.
- Some types of RAR archives. The error appears for archives that contain unencrypted list of files in their content. Also, we don't support the latest RAR5 format yet.
The remaining file types are supported in almost 100% of the cases with a few exceptions.
So, What's Next?
We do our best to support as many files and their internal formats as possible. If your file was not accepted for processing, submit a ticket to the support team.