https://us.community.samsung.com/t5/Galaxy-S21/UI8-Android-16-update-SIM-not-recognized/m-p/3408763#M97602 Pull the sim card and put it in a known good working device. Verify the sim is working. Place sim back in trouble device while powered off then turn on. If problem still persist, try re flashing the firmware via smart switch or odin.<BR /><BR /><A href="https://www.samsung.com/latin_en/support/mobile-devices/how-to-fix-the-no-sim-card-detected-error-on-samsung-galaxy-devices/" target="_blank">https://www.samsung.com/latin_en/support/mobile-devices/how-to-fix-the-no-sim-card-detected-error-on-samsung-galaxy-devices/</A> Tue, 18 Nov 2025 12:16:30 GMT MarvinMod2 2025-11-18T12:16:30Z