How to determine that an index is not damaged or corrupt.

To verify an index, dtSearch scans all structures in the index and performs many detailed checks to validate all data in the index for consistency. 

Using the dtSearch Desktop, click Index > Index Manager > Verify Index to verify an index. If the index does not appear in Index Manager, click "Recognize Index" and select any of the *.ix files in the index folder to add the index to the list in Index Manager. 

A quick way to check than an index is present and generally intact is to create a WordListBuilder and open it with the index path. If the WordListBuilder can be opened, all files in the index are at least present.

Building and Maintaining Indexes