"SYLK: File format is not valid" error message when you open a file in Excel for Mac

For a Microsoft Excel for Windows version of this article, see 323626 .


When you try to open a text or comma separated variable (CSV) file, you receive the following error message:

SYLK: File format is not valid


This problem occurs when you open a text or CSV file and the first two characters of the file are the letters ID (uppercase). For example, the text file may contain the following text:

123, open
456, closed
Note This problem does not occur if the first two characters are lowercase (id).


To open your file in Microsoft Excel, first open the file in a text editor and insert an apostrophe at the beginning of the first line of text.

How to Insert an Apostrophe

To add an apostrophe to the beginning of the first line of text in your file, follow these steps:

  1. Open the text file in a text editor, such as SimpleText or TextEdit. Click to place the insertion point before the first character in the first line of text. Press the apostrophe key on your keyboard (').
  2. On the File menu, click Save. Quit the text editor.
  3. You can now open the file in Excel.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

A SYLK file is a text file that begins with "ID" or "ID_xxxx", where xxxx is a text string. The first record of a SYLK file is the ID_Number record. When Excel identifies this text at the beginning of a text file, it interprets the file as being a SYLK file. Excel attempts to convert the file from the SYLK format, but is unable to because there are no valid SYLK codes following the "ID" characters. Because it cannot convert the file, Excel generates the error.

รหัสบทความ: 215591 - การตรวจสอบครั้งสุดท้าย: 18 ก.ย. 2011 - ฉบับแก้ไข: 1