I lost a significant amount of data from an excel spread sheet suddenly

Hello, I am using Libre Office version on a 2011 Macbook air running MacOs Sierra 10.12.6

I have been using the same excel sheet for months and saving it to Dropbox. Suddenly I went to open it and data is missing randomly from all of the tabs.

Using other computers to open the document with excel shows that it can’t be opened with excel anymore.

I have no time machine backup and I have searched LibreOffice for a backup and there isn’t a back up there.

First question is obvious and I fear hopeless: is there something i can do to get the data back?
2nd question: what the F happened?

You don’t mention what file format you use to save, seems an MS file format. If xlsx you can decompress the file and try to find those data inside it.

But it’s really strange a random missing data on different cells in different tabs, by a malfunction issue.

One possibility, is that having selected several sheets, deleting data in some of them it’s deleted on the whole selected sheets.

I don’t suppose you can help me “decompress the file and try to find the data inside it”

If you edit your question, you can upload your file here in edit mode.

I have added the file in question. If anyone is able to open it and get the missing data, I would appreciate it.

xlsx and native LibreOffice files are saved in a compressed format of the old ‘.zip’. You can change the extension to .zip, then open the file with a program like WinZip, but only if the file isn’t damaged.

You save to dropbox. That sounds very ominous to me. Do you (1) open the file from dropbox, edit it and save to dropbox, or do you (2) copy the file to your hard drive, edit that, then copy the edited file to dropbox? If (1), there’s a risk of data loss if the connection fails, and it will take some time to send the file to dropbox, more than when you save it to the hard drive. Now if you tend to close LibreOffice rather quickly, or just turn off the computer when you are ready with it, it’s just possible that Libre doesn’t get the time to send all data and your file can get corrupted. I don’t think that this is what happened in your case, but it’s worth considering.

I do save directly to dropbox. I think: “data loss because of connection failure”, is the most plausible cause. I live on an Island and we have been having issues with our connection lately. Upsetting that if there is a connection failure that the systems in play would choose to overwrite a healthy document with one that has less data in it. Developing nation issues, I guess. Catalina Island, California. I’ll change the extension and see if that helps.

I changed it to .zip and when I opened it I couldn’t make sense of the documents. I have attached it in its original xlsx form if you have any more suggestions/help/advice.

When the connection fails, systems have little to choose from. The same may happen if you work with files on a USB drive. If the USB drive is extracted too early, the file may not yet have been written. If you use too much force, the drive may get damaged. If you expose it to a magnetic field, the data may get corrupted. If you work for many hours on a file and don’t save it now and then, you risk data loss when there’s a power outage. Etc. Don’t rely on fallible systems more than you need to.

I forgot that if you also have many images in it, that will further increase the risk of data loss.And lastly, if the dropbox servers fail and your data gets wiped, you lost all of your work, anyway. Always keep copies of important files on your own computer or an external storage device.