Haven't managed to reproduce this error, but it's interesting that there have now been two reports.

If you open the script and take a look at it, you will see that the c.active field is referred to six times, in the lines which give a breakdown of remaining actions. Short of asking you to send me your database, or an encrypted version of it, there are two solutions:

1. (Gordian knot) If you can do without those details, simply delete that block of six lines from the script,
2. (221b Baker St) If you are feeling investigative, try eliminating them one at a time, to see if the problem can be narrowed down ...