Problem with opening the dataset

[Ridvan Peshkopia]

Hi Stata community. I am trying to open a .dta dataset, which I have been working on for the last four months (and quite a few hours ago as well). Now could not open it, and Stata tells me that file is "not Stata format." Meanwhile, I am quite sure that I have not changed the dataset format (I only use Stata for statistical analysis and no other format). Any idea what might have happened to my dataset file and how to open it? Thanks in advance.

Btw, I was trying to attach here the dataset for anyone who might want to check out, and it gave me this message: Invalid file data

[Richard Williams]

Do you have a backup copy in case this one has gotten corrupted? Are you using an older version of Stata than you were before?

[Marcos Almeida]

You may wish to read this thread.

[Ridvan Peshkopia]

William, thank you. Marcos, thank you for your advice. Yes, indeed, the problem that Alexandre has experienced is exactly my problem. Although he has resolved the problem, I am not quite sure how to follow Nick Cox' advice. How to open it with text editor? How to use the "type puzzling.dta command"? I wrote to them as well.