Trouble using Index for segment in ItemPath of JTree

Using Silk4J v16.5

I am having trouble using Index as a segment in the ItemPath for a tree (JTree).  Using text is OK, but when I change to an index it fails.  Because the items change over time I really would prefer to use an index.

Here is an example of where it fails -

desktop.<JTree> find("Element Editor.Element List").clickNode("/Element List/[10]");

This is the error I get in True Log Explorer - error unclosed group near index 2.

Using the text instead of index works.  Using text and index works. 

I tried using escapes for the opening bracket in the final segment but, that did not work either. 

Any help would be greatly appreciated.

Thanks.