Spotlight doesn't search for files and folder

[thinhpham]

Hi all,

I'm on El Capitan and have been experiencing this problem: Spotlight suddenly stopped searching for files and folders, only apps, contacts and other information showed up. I realised that if I restart my Mac, it would get back to normal but after a period of time, that problem returns. I tried to re-index Spotlight using these commands:

mdutil -Ea
mdutil -ai off
mdutil -ai on

but failed to do so, this message appeared:

Error: Index is already changing state.  Please try again in a moment.

I've been experiencing this several times for weeks and tired of restarting my Mac while working. Can anyone suggest me how to fix this?

Thanks,