I received a message that I couldn't open.

It may be that the text is incompatible, but in your case, everyone's text messages can't be opened. It's probably not that simple, because it's rare that everyone's mobile phones are incompatible with each other.

If you confirm that the MMS is not sent by others, your mobile phone does not support it, and it should be a signal problem. In addition, if it is a multimedia message, it is likely to be opened in garbled code. Even some expressions unique to other people's mobile phones may not be opened or supported in your mobile phone, such as active expressions.

As for the dormitory signal problem, many schools have it. Some dormitories in our school simply don't even have a signal, but it only happens in that dormitory. The reason is that some other networks in the school may be covered, such as the school wireless network, local area network, other broadcast signals and so on. At this time, it is not a mobile phone problem. There is no way to solve it for the time being.

Does it help? ^_^