Flashing folder issue booting up in safe mode

See the https://support.apple.com/en-us/HT204323

from >System Preferences>Startup Disk > select your Macintosh HD and test

<<I can boot in safe mode and if i do a restart in safe mode, the macbook boots up ok.>>

my mistake, I only see the OS X base system when In recover but can see when running disk utility from the desktop.

From Recovery — no Macintosh HD

Disk Utility from Desktop — you see the Macintosh HD (and you ran DU from there; no errors?)

SafeBoot mode— the Mac boots up, and you can log in?

is this all correct?

reference this kb https://support.apple.com/en-us/HT204323

<<I can boot in safe mode and if i do a restart in safe mode, the macbook boots up ok.>>

I've tried what you advised and no errors on the disk after running first aid.

When I ran reinstall the macOS can't find any destination to select

So in Recovery you see Macintosh HD, you ran first aid and it said no errors;

yet switching to reinstall the macOS does not see the same Macintosh HD ?

<<>System Preferences>Startup Disk > select your Macintosh HD>>

Rebooted and rebooted to normal boot.

And this solved your problem?

rebooted to normal boot.

Thank you

Good computing sbuk2503 !

Boot into Recovery (Command R) and from the dropdown menu: Utilities>  Disk Utility> run the First Aid on your Macintosh HD. If errors are found and repaired, run again until no errors reported.


Recovery http://support.apple.com/kb/HT4718

If need be you can reinstall the macOS on top of your existing macOS from this same recovery.