Error: Could not find installable ISAM
This error is thrown whenever starting a capture or when opening an existing batch in the Indexing or QA modules.
The error is tied to Advanced Indexing configured within the Capture Profile.
In the event encountered, the solution was to wipe the Schema.INI file from the configured Lookup's location and Edit/Save the lookup within Capture. This will create a new schema.ini and eliminate the error.