Forum Discussion
Excel cannot be open because the file format or file extension is not valid
Hi All, There is an excel.xlsx file in my computer. That file was deleted by me and later recovered by a tool that recovers deleted files. There is no error in the last modified date and the siz...
The contents of the file have completely been overwritten with NUL bytes:
So there is nothing you can do with this file. Do you have a backup copy of the workbook from before the problem?
I have a copy, but it is not up-to-date
Is there a way to unlock the damaged one?
Is there a way to unlock the damaged one?
As I mentioned, the damaged file does not contain any useful information any more. It is not an Excel workbook or any other file type; it is entirely filled with bytes of value 0.