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 a SYLK file. Excel tries to convert the file
from the SYLK format, but cannot do so because there are no valid SYLK codes
after the "ID" characters. Because Excel cannot convert the file, you receive
the error message.
For more information about a similar error message, click the following article number to view the article in the Microsoft Knowledge Base:
224134
Error message: File format is not valid