my personal rule:

  • In the development stage, programmers should have full access but data are anonymized.
  • In the test stage - only some qualified developers get limited access
  • in the production stage, neither users nor developers should have access to the studio or terminal.
    Access is given only temporary, to top experts for error analysis.
    That's like the doctors that take care of places of your body you won't' show to anybody else.

     

normally there is no need for such "wrapper"

typically %Save() returns a %Status object and then it's up to you to analyze it in case there is an error.
In the situation described here, all you can do is just a retry. 
- it could be a Lock collision 
- or the LockTable is full.  
Instead of fiddling in system parameters requiring a restart, you just wait and retry. 

if you are curious how often this happens you may add a loop counter. for further decisions

Docs of $G say

variable                            A local variable, global variable, or process-private global variable, subscripted or unsubscripted. The variable may be undefined. variable may be specified as a multidimensional object property with the syntax obj.property.

similar Docs of $D say

variable                            The variable whose status is to be checked. A local or global variable, subscripted or unsubscripted. The variable may be undefined. You cannot specify a simple object property reference as variable; you can specify a multidimensional property reference as variable with the syntax obj.property.

but Title in your case is $li(^CinemaooFilmD(3),1). So neither $G() nor $D() is approriate.

you can delete the class in Studio or from SMPortal.
so you delete the class DEFINITION and the related table DEFINITION. but no  data.

BUT.

DROP TABLE in SQL also deletes the data  AND the definition because this is part of SQL Standard. (Se also MySQL)

I'd suggest you take some time to really read the documentation or consume some online training.