Previously you had used an earlier version of SPSS, PASW or IBM SPSS Statistics and the syntax used worked without issue.
Now when the syntax is run it displays a warning number 237 and fails to run the analysis.
The message is similar to:
>Warning # 237
>SPSS Statistics read a line of syntax which contains one or more characters
>which are invalid in the current locale. These characters have been converted
>to question marks.
From IBM SPSS Statistics 21 the default encoding is unicode (UTF-8) and if the file was saved in an earlier version of Statistics it would usually be saved as system locale for the encoding of the text in the syntax file.
Resolving the problem
Open IBM SPSS Statistics and select Edit>Options and on the 'General' tab select the system locale as Unicode, if it is not already selected.
Restart IBM SPSS Statistics.
Once IBM SPSS Statistics is started again open the syntax file by File>Open>Syntax. and select the file to open, click on the 'Open' button.
Once the file is open, click on File>Save As and overwrite the file, note to ensure the encoding is set to Unicode (UTF-8), if it has not defaulted to it.