salut!
Any help is greatly appreciated.
The line
Attribute options Default ""
should read
Attribute options -default ""
why ...
The code has been working for about 2 years without giving any error
i can't explain right now (and i don't have the time to take a closer look), i can only state that it shouldn't have, in the end. without correctly specifying the default value, the string items 'Default ""' are passed to the application-level "constructor", i.e. Sim->init(). as init does not accept any arguments, you run into the error condition reported.
bien à toi
//stefan