Original topic:

UI8/Android 16 update SIM not recognized.

(Topic created: 11-26-2025 02:47 PM)
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bwrite
Asteroid
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Galaxy S21
Galaxy S21FE 

After updating yesterday to Android 16/UI 8, my SIM card is no longer recognized. 
My phone tells me to insert a SIM card when 8 try and turn mobile networks on my phone diagnostics say the SIM card is good, just can't connect to a network. 
I can't make any changes as the 'Access Point Names' and 'Network Operators' are greyed out.
Also, when I go to check for system update it says there's no info about the latest update... And I get an error message if I try and run a check...
Did my update somehow get botched? His so I force a re-update?

I switched from Verizon to Mint Mobile 6 months ago, and this is my first major update since. but I bought the phone already unlocked. Did this update somehow reset it? Why can't I make changes like I did when I switched networks?
Will a factory reset get me around this? (Able to modify my access point and network?)
Desperate to not buy a new phone just yet ๐Ÿฅบ

95 Replies
melon83
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Galaxy S21

Same issue. After update to OneUI 8 can't connect to network. No access to sim manager. Sim card works on different phone and other sim card doesn't work on my S21FE. Try every advice from Samsung online help and chat. Problem still exist. If Samsung won't fix it in quick period of time I'll stop recommend this brand ๐Ÿ˜’

 

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Ad21FE
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Galaxy S21

With the number of views this thread counted, many phones may have been affected. I hope this will be resolved immediately.

No Network detected, no IMEI, and no Baseband here since Nov. 24. ๐Ÿ˜ฉ Good thing I kept my old iphone and insert my sim there, it works.

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fuzzyduck
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Galaxy S21

I experienced this issue just after android 16 update on my S21 FE.  I was able to fix it with a factory reset.  In my case the IEMI could not be displayed via the settings about phone page.  Without the IEMI the phone cannot authenticate or access the SIM.  If you cannot read your IEMI you may have the same problem as I and a factory reset may work.  Unfortunately this process deletes all your apps and data, so back up anything you want to save. 

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fuzzyduck
Constellation
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Galaxy S21

Sorry IMEI, not IEMI.

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Ad21FE
Asteroid
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Galaxy S21

Thank you for your response and for sharing your experience. I will probably try it once I get home. 

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Ad21FE
Asteroid
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Galaxy S21

It goes well for me too, @fuzzyduck.
To those who have the same issue, this may or may not work, I'm not responsible if something bad happens to your phone so backup your data and proceed with caution.

Hereโ€™s the process I followed:
*Backed up my phone data to my PC using Samsung Smart Switch software. (you can search and download the software from Samsung website and install it to your PC)
*Performed a factory reset on my phone.
*Rebooted the device and the network signal returned.
*Used the Smart Switch app on both my PC and the phone to restore the backed-up data.

The data restoration only took about 5-8 minutes, followed by another 14 minutes for the phone to download and configure all the apps using wifi (recommended). While I had hoped to solve the issue without wiping the device, the factory reset successfully restored my network connectivity. O, well.... Thanks again @fuzzyduck.

Members_8bvIt1G
Constellation
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Galaxy S21

Same for me with the S21 FE

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Members_Jj13lJe
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Galaxy S21

Have the same issue after the update. Does not detect the SIM card at all and sim status/imei shows unknown

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melon83
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Galaxy S21

Hi mate. On my S21FE fully factory reset resolved issue. First backup data on smart switch then reset and on my screen appears network signal. My mobile works perfectly. Hope it will work for you.

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OrangeCrush
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Galaxy S21

Had exactly same happen to me on my S21

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