Search string must be specified

You have to specify a search string. This error has the following cause and solution:

• You tried to perform a search operation without a string for comparison.

  You must specify the search string. While you can specify a zero-length string ("") as a replacement string, a zero-length string has no meaning as a search string.

For additional information, select the item in question and press F1 (in Windows) or HELP (on the Macintosh).