1. Create a new project
2. Open the Index Manager from Windows-> Search -> Index Manager menu
3. Create a new Index by clicking on the "+" button on the left (doesn't matter the type of index)
4. From the option rollout of the newly created Index, check the "Disabled" checkbox
5. Create the index by clicking on the Create button
6. Save it somewhere in the project

At this point, the index should be grayed out in the list since it's just been deactivated

7. Close the Index Manager and Reopen it

Result: Disabled index disappeared from the list
Expected: The disabled index should remain in the list

The only way to get back the index in the list is to edit the index file and manual change the Disabled properties to false.