Latest version of ID, on a PC running Windows 10.
I have an InDesign Book consisting of roughly 10 files, of varying sizes, all INDD format, which I've been indexing using the Index function. Some index entries reference pages across mulitple documents. I've generated the Index the usual way, including all Book documents, and I've found that for a couple of entries, the page references haven't been in numerical order. I'm guessing this has to do with indexing them out of order, but surely the tool should correct this?