I was given a .xlsx format file to do a simple change. But Microsoft Excel won't let me save to .xlsx. After saving the file this error message occurred:
@Harrypope Your Office install may not have the compatibility packs installed to read and convert the 2013 version of this file while using an older version of Excel. You can run windows updates and have it check for these or can download and install them from here. Let us know what your results are.
Hello Harry When you get the "unexpected error" is there a numeric code as well? Also, select the file and open its properties. Just below "attributes" look for a check box being there with the text similar to "this file came from another computer do you trust it". Check the small box and save. Try to reopen / resave the file.