Continuous reboot loop after Marshmallow update

[Camprats]

Just because something happened after the Marshmallow update does not necessarily mean it happened because of it, but I have my suspicions.

The tablet started after the update process was complete.  I shut it down a couple days later and it will not restart.  I power it on, then get the expected "Android"  followed by the waving blue screen.  The blue screen goes for half a minute or so, freezes then goes blank and the process starts all over again with "Android".  This loop will contiue until I shut it down with the power button and volume up.

I did a software reinstall using PC Companion and still got the loop.  Called Sony and was told to use Xperia Companion and Software Repair.  Did this and am still getting the loop.

Wrote an email to Sony Support stating what I had done, which of course they did not read.  They told me to use Xperia Companion and do a Software Repair.

Does anyone have a suggestion what I might do next?

[Uliwooly]

@Camprats

If the tablet has a SIM and/or SD cards, remove them and try again. 

[Camprats]

We are on the right track!

If I remove the SD card the tablet will boot up.  If I put it back in I get the loop.

Does this mean an SD card cannot be used with Marshmallow, or is there a setting I need to change?

[Uliwooly · Accepted solution]

@Camprats

Could you test a different SD card? perhaps the SD card it's corrupted. 

[Camprats]

That was the answer!  A corrupted SD card.

I put in a different SD card and it booted up perfectly.

Thank You, Thank You, Thank You!

[Uliwooly]

@Camprats

Excellent 

[slartibartfast]

Thanks for this solution I got the same problem on a Xperia Z3.

I did one factory reset after getting this problem, only to have it happen again when i rebooted.

So you have saved me reverting to Lolipop