We recognized the file format, but our reader was not able to read it successfully. The file may be corrupted, or a higher version than we support. Try (if possible) saving it in another format, or an older version and re-upload.
Two particular situations where we found this error were password protected files, and files with the wrong extension (a very typical case are RTF files renamed as .DOC). Please ensure your file is not password protected, and if it's extension is .DOC, try renaming it to .RTF and uploading again.
If you haven't been able to make our reader count words successfully an approach that will work, if it is feasible for you, is opening the document you are uploading, and saving it as a text file. If the program doesn't have a direct option to do this, you can sometimes copy all the text inside of it, and paste it in a new Text Document, and then upload the .txt file.
Depending on the file format, this may be possible or not, and it might not be 100% accurate (some text might not get exported), but it will give you a decent approximate amount, if you don't know how many words are in the document.
If you do know how many words the document has (at least approximately), you can simply enter them in the "Word Count" field at the start of this Search Step.