I have Samsung Galaxy s6 and not updated on marshmallow 6.0 tell me how can I fix.

[AC Question]

I have Samsung Galaxy s6 and not updated on marshmallow 6.0 if update then not working sim error and other. Please tell me how can I fix it. I have SM-G920P. I lived in Pakistan.

 

[belodion]

You're saying that if you update, there will be SIM and other errors?