How can I import an iWork Numbers spreadsheet?

I downloaded LibreOffice 4.2 to both my iMac and my Windows 8.1 laptop. Neither version will open a Numbers spreadsheet from my Mac. Any idea what I am doing wrong? The error I get is “General Error. General input/output error.” I tried opening a number of different spreadsheets, transferred by email and flash drive. The character set I used is Unicode (UTF -8). I used defaults for the options.

How many different files did you try to open? Could you rewrite your statements into a question? Explicit questions are easier to answer than implicit ones. Thanks

Oh, and tags help your question to be found later, so could you perhaps add a few related tags too? Thanks!

It is important to note that you will need to first export the iWork Numbers spreadsheet to either Excel (XLSX or XLS) or CSV file format in order for LO to be able to open the files. No native support of iWork formats is offered AFAIK. This may well be unrelated to the particular error you are experiencing, which is described in greater detail in this answer.

Related question here.

I exported the spreadsheet to XLS and it worked. Thanks a lot for your help.