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