Unable to find bootable option

[Hafidh Ikhsanu]

I have a nokia lumia 520. The error it says "Unable to find a bootable option". please help me to fix it

 

[Scienceguy Labs]

Have you performed a soft reset?

Press and hold the Volume down and Power button simultaneously until*phone*vibrates, then release both keys.

If that doesn't work, you might need to download the Windows Device Recovery Tool and flash your phone with a fresh OS. Get that here: https://support.microsoft.com/en-us/help/12379/windows-10-mobile-device-recovery-tool-faq