Hi km.

What OS version are you using? I have a Moto G 3rd Gen since April, with a 16 Gb SD card class 10, and never had this issue you described. I have Android 5.1.1 on the Moto G, that's why I ask, maybe is the OS, not the hardware.

Regards.

It has now been 3-4 months with no problems. The difference this time round is that I have no apps on the SD card, only media files.
I am not willing to say the issue is sorted (yet), but, it might be worth trying.
If you habitually move apps to your external storage, try not doing it. I know it is not an option for some gamers, but, for everyone else it may be worth a shot.

Marshmallow.

It may be the OS, but something is actually trashing the SD card, CREATING bad spots on them.

I found an 8GB class 4 card.  We'll see in a few weeks if it gets trashed or not.

All I have on it are MP3s

I have had the same issues as all of you but with a different phone. My phone is a Motorola 2nd Gen with 4G lite. 

I contacted their online support and thought I'd include the entire chat here for all of you to read.  Hope it sheds some light on this for some of you. I'm heading out to buy a new sd card soon.

-START OF SUPPORT CHAT WITH MOTOROLA-

Karen: Hello! Welcome to Motorola Canada technical Support! How are you doing today? My name is Karen. How may I help you?

 Me: Like many Motorola owners... my phone has decided to no longer function with, or read, my SD card.

 Me: This is a recent issue that surfaced after the Marshmallow update.

 Karen: I am really sorry to read about the inconvenience you are having but I will be happy to assist you today.

 Me: I have been reading online about this issue with many other marshmallow users and some of them have purchased up to 4 different (and new) sd cards that all eventually fail... rendering them useless.

 Karen: Could you please provide me the IMEI number of your phone?

It can be found on the side of the box, under Settings > About Phone > Status, or by dialing  *#06# on the main screen of your handset

 Me: Ok... hold on...

 Me: Number Provided to Tech Support

 Karen: Thanks.

 Karen: Let me ask you, have you tried any troubleshooting step on the device? 

 Me: Just tried reinstalling the card, tried reformatting it, tried using it as both internal and external storage, but it won't format and states this card is not supported. Also tried it on my computer but it can no longer be read by it (or anything for that matter).

 Karen: I see, I am sorry for the inconvenience.

 Karen: Do you have this problem only with this card or with all?

 Me: I put it in my wife’s phone as well... we have the EXACT phones... however she has NOT upgraded to the new operating systems... and when I put the card in her phone it used to recognized it... but now it does not.

 Karen: I see, may I know what type of card are you using? 

 Me: SONY...Micro SD... 32 GB... 700 MB/S… HC

 Karen: Do you see any number on the card? 

 Me: wow... yeah hard to read... hold on...

 Me: 90973539

 Karen: I mean something similar to this  https://motorola-global-portal.custhelp.com/euf/assets/images/faqs/Marshmallow/sd-card/sd-1.PNG

 Me: it also says... SR-32UY2

 Karen: I would like you to verify that because for this Android version. We recommend use of a  high speed card , such as a UHS-1 type.  

 Me: Nothing on this card refers to UHS-1

 Me: not that I can see

 Karen: Then  this could be the reason why it does not work properly on the device.

 Me: it worked fine until the latest operating system update... so how long has UHS-1 been a preferred SD card type?

 Me: Remember... other people have tried up to 4 different cards that all eventually fail...

 Me: So are you recommending that I purchase a UHS-1 type sd card?

 Karen: All devices are different depending on the usage, we may have to check if those have tried high speed cards.

 Karen: I would recommend you to format the card from a computer, but if the issue persists, the best will be to upgrade your SD card.

 Me: The card will NOT format on my computer... It no longer shows up when I try to view it with my computer

 Karen: Oh I am really sorry, then in that case you can try to format it from the other phone and then on the PC. 

 Karen: I would suggest you to try as well another card on the phone before purchasing a new one.

 Me: Has Motorola recommended using a UHS-1 SD card with this phone from day 1... or do they CHANGE their recommendations of SD card types based on each new operating system?

 Me: I don't have any other sd cards... do people just have them laying around the house normally...?

 Karen: Some requirements are changing depending on the latest versions, since systems are beings upgrading everyday the same happens to the SD cards since lower cards could not work properly. 

 Me: So would a higher-speed card ALWAYS work as expected even after major operating system changes or updates?

 Karen: Correct, cards has to be up to date as well.

 Me: Okay hold on a minute here... you need to clarify exactly what you're telling me. Are you saying that it's possible that each time Motorola updates or changes the operating system for this phone that I may have to purchase a new SD Card to ensure it works?

 Karen: Not exactly, it could pass many years. 

 Me: I see... but there is still that risk at sometime that the card may need to be updated.

 Me: I have had my phone less than 1 year and already my sd card is no longer compatible with my phone... as a matter of fact the phone has now destroyed the card... nothing can access it or read it anymore...

 Karen: This cannot guarantee but as mentioned it could pass many years. 

 Me: Here's what worries me... other people have tired a lot of different cards and eventually they all fail... this obviously costs money that no one can get back. Are you aware of any issues with these phones that can cause the SD Cards to become unusable...?

 Me: I'm willing to purchase a UHS-1 SD Card but if it eventually fails I'm gonna be real unhappy. However before I jump to conclusions I will have to try that first.

 Karen: But as I was telling you, every phone is different and we do not know what type of cards they have used.

 Me: Ok true... fair enough...

 Karen: I understand you, in this is why I recommend you to try to get first another card, any other and check if that work on the phone.

 Me: I will try the UHS 1 SD Card

 Me: Does you have an exact recommendation? Sony? Sandisk?

 Me: In other words... are there any SD Cards that Motorola recommends for use in their devices?

 Karen: We cannot recommend any brand in specific but as far as it is a higher speed car it will be okay.

 Karen: You can find more details about using SD card on Marshmallow:  https://motorola-global-portal.custhelp.com/app/answers/prod_answer_detail/a_id/109134/p/1449,9582

 Me: Ok so... if I purchase a UHS 1 SD Card will it automatically be fast enough?

 Karen: Correct but if you have the chance to try another SD card before purchasing it, it will be better.

 Me: I have no idea how to try another SD Card before purchasing it. My current card transfers data at 70 MB/s.... what does Motorola recommend?

 Me: Does Motorola  recommend a minimum MB/s for these phones?

 Me: That might help me in my search

 Karen: This could depend on the card that's why the only we recommend to check is if the card is  high speed.

 Me: Okay... well thank you for your time. Hopefully a newer faster card will work.

 Karen: You're welcome!

 Me: Have a great day!

 Karen: Thanks! 

 Karen:  I wonder if besides that you have any other question or something else that I can do for you?

 Me: Nope... that's it....

 Karen: Alright!

 Karen: Thank you for contacting Motorola chat support. Have a Wonderful day!

 Karen: Bye! 

Thanks for that info, but I think it may not work.... I have a UHS-1 micro SD card in my Motorola 3G and I get exactly the same problem as everyone else - it worked for a few months after Marshmallow update and when I formated it to be internal (so will probably work for you too at first), then I got the problems of not recognising it. I refomated it and all OK, then a few weeks later it went wrong again. Then I left it, and it seemed to cure itself, but has just gone wrong again after about a week.

So it seems a terminal problem of formating the SD card as internal memory. It doesn't seem any soloution is out there until the update to the operating system is fixed.

I'm going to revert having the SD card as external storage only - like others have said - which is a shame as the phone now will have limited memory for those apps that have to run internally. Turns a decent phone into a second-rate one...

Hi all,

I have formatted an old slower card as internal memory and I have just not put any apps on it and I am backing up everything to the cloud regularly. Oddlyy this old slower card has not had any problems so far. So I think it is definitely either the operatig sytem or Motorola/Lenovo's version of it which is the problem and not the cards. Maybe it is to do with how apps read and write from it? I'm pretty sure that unless this problem is reliably fixed I will not get another Motorola phone next up.

Hi again.

Here's another thought on this... by coincidence yesterday my wife got exactly the same message on her Motorola G4 - the first time since she put in a UHS Kingston SD card. It happened the first time she used an app: the navigation app Here.

Now, I have that app too, and I can't remember but it's possible the first time I got the error it was when I used that. But I am also fairly certain the second time I got the SD card error after reformating (as I mentioned above) it was after using Here again.

My wife unistalled Here and says her SD card works fine now. We'll wait and see what happens in the future.... But possibly the fault comes from apps that are on the SD card and are actually incompatible with the operating system? I don't know, but worth thinking about what apps you have.

Hope this helps!

I've been having similar issue with SD card dropping apps or SD card missing error. I have a SanDisk uhs-1 . After contacting Motorola support and factory resetting the phone the problem continues intermittently. I contacted customer support again today and they said to send the phone in for repair. what are they going to repair if problem is software-related and only errors intermittently? 

I read somewhere that some applications are not compatible with Android 6, some APIs are not updated to use on MM. Maybe this has something to do with what is happening.

I can say for all that is posted here that MM was delivered without the proper testing, with a lot of bugs yet in the OS. Lollypop is quite more stable, anything of this happens using 5.1.1.

Hope you find the solution of this. I think that MM is the problem here, not the phone itself, o the SD cards. As I mentioned, I have my Moto G 3rd Gen running Android 5.1.1 and no issues like these happened... is quite stable and fast. This is an indicator that the variable here is the OS.

Hope that Google releases a 6.x version to fix all this, or maybe will be Android 7 ??

Regards.