Why does my SD Card freeze my Lumia 950 on start up?

[alexx17]

my old sd card makes my new lumia 950 to be stuck on the boot up

so i just got the new lumia 950 xl in the mail after i put in my old sd card the phone gets stuck on the boot up is it a phone problem or is the card broken

 

[Rose640]

Re: my old sd card makes my new lumia 950 to be stuck on the boot up

It has to be at least class 10. Also, i had some similar issues with my 640 where i had to format my SD card in order to work in my new Lumia. So you could try the same.