Damaged data downloaded

The data of some participants of my experiment are not being saved or the downloaded files are “damaged” and cannot be read. Could someone help with this? It would be really important to get those data back. Thank you.

Could you give more information as to what the problem is? For example, how did you establish that the data was damaged? How did you establish your participants completed the experiment?

Does this post of yours refer to the same issue? Some data are saved, some data lost - can I get the data back?