Hi,
What happens in the type of merge you are explaining is that a Word document is linked to an excel spreadsheet to retrieve it's information. So typically, one of two things has happened:
A) You moved or removed the excel file for it's original location.
B) You have taken out the column headers to designate what each column contains. It's likely that you have prolly done this. I have a user that tends to do it all of the time. To get it to recognize the excel file again, insert row 1 and put in column headers that are likely. Save the excel file. Re-open the word merge document and it should at least now open. Look for all the field places, they will be designated with "<<>>" Make sure the field names match the column headers. If they do, merge away. If they don't, exit the Word document without saving changes, open your excel spreadsheet and correct the column names. One tip to remember, if the column name you want is "Last Name", in the merge file it will appear as "<<Last_Name>>"...the "_" signifies the space.
Good luck.
Smiles...Shearbec