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mistermudd's profile

Contributor

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3 Messages

Wed, Apr 11, 2018 4:12 PM

"SIM Not Allowed MM#3" on Galaxy S8 After Recent Software Update

Greetings,

 

I am using a Samsung Galaxy S8 which I purchased new from AT&T as well as the AT&T-provided SIM card. I have not made any modifications to the device, and it has not suffered any trauma.

 

A few days ago, there was a software update. Since the update, I have found that I periodically get a notification on my phone which states "SIM not allowed mm#3". This is then followed by the device not allowing any data/sms/phone connectivity other than emergency calls. After rebooting the device, the error is cleared and the phone is useful again until the error recurs.

 

I have found that the error only occurs while I am at work. I work in an area that has very poor/spotty connectivity. The error surfaces after going from having no signal to having weak signal. While I am at home or in any area that has strong signal, the error never occurs.

 

I believe this to be a problem caused by the recent software update.

 

Is anyone else experiencing a similar issue? Is anyone able to provide advice on how to solve this problem?

Contributor

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3 Messages

5 years ago

Surely I can't be the only one experiencing this issue. Having to reboot my phone several times daily  is quite burdensome.

Contributor

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1 Message

5 years ago

I have this same problem and I have a S7. My husband is also have this problem (also S7). We went to AT&T store and the guy replace my SIM card. He stated the problem was with the SIM. Well, shockingly we are still having this problem. Took screen shots of the errors. Will be going back to see if the problem can be fixed there. 

 

I also have found that the error only occurs while at work. I also work in an area that has very poor/spotty connectivity with having no signal to having weak signal. Never seems to happen while at home, we have great service. Verizon works well where I work and this is pushing me more and more to switching to that carrier. It is sad because I have been with AT&T for over 15yrs. Was trying to wait to see if the rumor mill was true and getting an AT&T tower put closer to where I work.

Contributor

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3 Messages

5 years ago

Sounds like you work where I do. Verizon service is much stronger here where I work.

 

ATTHelp

Community Support

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203.8K Messages

5 years ago

Hello @mistermudd,


Any SIM error can raise a concern.  Having to reboot the phone periodically to correct it can definitely be a hassle.  We have some troubleshooting steps to try!


If you haven’t already, it is recommended to get a new SIM card in the event the current SIM card is no longer compatible with the technology enhancement from the software update.  If the new SIM card doesn’t help, please feel free to visit our Troubleshoot & Resolve Tool. Here, you choose your Phone Manufacturer > then choose your Device > under Device/software issues, please choose SIM card.  Here, you can follow a troubleshooting flow to determine the best resolution for your device! 


If all else fails, the last step will be is a factory reset.  Please click here for our Device Support link.  You can search for Backup & Restore to save your information and then search Reset Device to perform this reset.  Alternatively, you will first go on from the Tutorials tab > on the left side column, choose Backup & Restore on the left side column > Here, you will find different ways to back-up your device prior to a factory reset.  After your backup, you would choose Troubleshooting on the left side column > Choose Reset Device in order to perform a factory reset.


If you still need further assistance, please don’t hesitate to contact us back!


Adam, AT&T Community Specialist

New Member

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2 Messages

So you're saying you're gonna pay for my new SIM card or deduct that cost from my bill? This is the equivalent of a hidden charge when none of us have done anything wrong.

Samsung Note 8

(edited)

New Member

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1 Message

2 years ago

I started having same issue today on LG phone. When I went to AT&T store, the tech took my sim card out and put it back in, and the phone worked again. She said that maybe I have a problem with the tray, and suggested to look into replacinv the phone, which is only 2 years old. But reading this, it seems like I am not the only one.

New Member

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10 Messages

3 months ago

I've got the same problem with a samsung s20 5g.

Replaced sim card. Still failed whenever I experienced no signal.

Att replaced with new S20 5G.  Worked a couple weeks, but now getting sim not allowed mm#3 anytime I leave coverage area.

This is getting ridiculous and is obviously a problem with the s20 and AT&T as they are designed and not working together. 

So many of the supposed resolutions are from 5 or more years ago and none of them work, not with two different Sims and two different samsung s20 5gs.

Is this ever going to be fixed or is this the new standard we have to just accept constant "glitches "?

Really would like a phone that works. It is after all a "mobile" phone. If it only works when I'm at home I could use a land line.

New Member

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10 Messages

2 months ago

Does no one have a solution for this? Am I the only one experiencing this?

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