Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
It is very hard to tell from info that you provided.
But it looks like you are tryng to read first character of non-existing string.
Check your arrays and first letter reading parts.