I’m trying to use the current Index from the For loop as an Index on the array to be used. But this error is appearing. How do I fix this?

This invocation calls a function that has the ‘decides’ effect, which is not allowed by its context. The ‘decides’ effect indicates that the invocation calls a function that might fail, and so must occur in a failure context that will handle the failure. Some examples of failure contexts are the condition clause of an ‘if’, the left operand of ‘or’, or the clause of the ‘logic’ macro.(3512)
