Upgrading From Spectra 1.01 to 1.5 Causes the "aRules" Error
In Spectra 1.01, it is possible for a container to have no rules. When upgrading containers from Spectra 1.01 to Spectra 1.5, if the container does not have a rule, you would see this error. This has been logged as bug 22204. Macromedia has provided a hot fix for this issue:
Upgrading From Spectra 1.01 to 1.5 Causes the "aRules" Error (Updated April 13, 2001)