Custom Attribute?

[Das Goravani]

I have this line of code

Do $ctask.tvO.$singlefilefind(prsavedviewname,#S1)

Now the #S1 is an attempt to get rid of a bug that keeps popping up. 

When this line executes, SOMETIMES it pops up an error and says “When evaluating it there is an unrecognized custom attribute”

My method which it names $singlefilefind() takes two parameters, a field name and then a search value, which can be a field again or a value in quotes if text or straight if number.. this method works all over the place and does not say Unrecognized custom attribute all the time.. no it does not. ONLY In this one place.. and usually when quitting the app.. 

So it usually works, and only bugs out when quitting and only in this one place.. 

Any ideas why? Is there something about quitting the app that makes your code stored in Objects not work correctly? tvO is an object, a task variable Object.. again this line of code works ALL OVER the place in my app and it doesn’t make sense why it doesn’t work here.