If you get something like the below in the SPSS output window
“>Error # 100. Command name: COMPUTE > >This command is not permitted before the beginning of file definition > >commands. > >This command not executed”.
simply either open a data file or manually insert a data point e.g. a '1' in the upper left corner cell in the empty spreadsheet .sav file. SPSS will only run syntax if there is at least one data point in its current spreadsheet file.