No Value{160} Error ?

[#1]

All, 
     I have a well functioning namespace that works fine when called on. However,  when I have this in a loop, it is throwing an error No Value{160}. It is generating a table that i expect - but half way through after building some columns it is throwing this error. Data is confidential and I can't share but I am perplexed why this would happen, despite the fact that reference variable points to the right table ? 

[#2]

Probably a min or max function is producing the error. I believe the number is a how-many-times count, and the argument to min or max is wrong. I'm looking at fixing the error message. Thanks!

[#3]

@Craige_Hales, 
        If that is the case, why would that error not occur when executed outside a loop ? I am thinking, there might be a link to table scoping and references. Have an open case with Technical support [SAS 7612441320]. Would love to show you a demo if you can make yourself available. Kindly let me know