Original topic:

UI8/Android 16 update SIM not recognized.

(Topic created: 11-18-2025 02:33 AM)
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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
tsmblacjman
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Galaxy S21
And they haven't a solution so now I cant call text etc.
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Mags2018
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Galaxy S21
Same. ๐Ÿ˜” Charging an old phone now to see if it still works. Did this just happen to you today?
tsmblacjman
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Galaxy S21
Yes
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JustPassingThrough
Constellation
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Galaxy S21
same problem. same phone. ATT. SIM works fine in hubby's phone so that's not the problem. ATT suggests having UBreakIFix refresh to Android 14 (?!), but they can't promise that it will work and could just make the problem even worse. sigh.
Omotara
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Galaxy S21

Having same issue, updated the phone this morning, made a call before the update and now there is no SIM detected.... can we have this looked into urgently.

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tsmblacjman
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Galaxy S21
Update. To no avail no solution from Samsung or repair shops. I did research and reflashed phone using Odin program and samfw.com to get the right version of android for my s21fe . And this worked and kept all my data I had. U can use this software it's free and plenty of how to . Just take notes and have a laptop or PC and good cord. Takes 10 minutes to do. U can get android 14 15 16 . I did the 16 refresh and no issues 2 days later
dig814
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Galaxy S21
You still good? I'm considering doing this but am now so irritated with Samsung I may switch.
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tsmblacjman
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Galaxy S21
Yes
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dig814
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Galaxy S21
I did the reflash today and it went well. All good. Advice for others. Use frija to get the firmware. Much faster and more stable than samfw
Use chatgpt to guide you through all steps. Just ask it to show how to flash your Samsung with Odin step by step. Beats having a useless phone but I'm gifting mine to my mom and getting an iPhone. First ever. ๐Ÿ˜Š
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tsmblacjman
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Galaxy S21
Sweet. Friday works good too . Either site gives same firmware. . But agreed Friday can be faster espnof ure downloading from a puter vs mobile. Glad it worked out for u.
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