SIM card cannot be detected, cannot open "SIM Card Manager" The SIM Card Manager on the Settings cannot be opened. The SIM, contacts, and messages also cannot be detected on my cp. Even the mobile data can't connect. It says "Insert SIM card", but the SIM card is already inserted.

What is the reason for this?
Some possibilities:


The SIM card is defective
The SIM is inserted the wrong way
The tiny metallic connectors of the SIM card plug are deformed (this is my personal experience)