UnsupportedOperationException at java.util.AbstractList.add

Question

I\'m having issues getting a block of code to run properly. I\'m not entirely sure WHAT this code does (I\'m trying to get a plugin that\'s out of date to work properly with

Answer 1

The problem is in the class of the list object that is returned by the get call. It doesn't override the add methods appropriately, and your code is therefore using the placeholder method provided by AbstractList.

There's not much more we can say without knowing what the list class is, and (if it is custom code) seeing the source code.