How to override all connection exceptions (throughout the program) with another custom msg

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C#

MySQL

entity-framework

hi, i write a C# program (Windows form) that work online , but many exceptions appears because of slow internet.
how to override all connection exceptions (Throughout the program(with another custom msg and show C# MessageBox.Show.

What I have tried:

i tried throw custom exception like this , but i want to write class that affect on all the program and appear automatically if any connection exceptions occurs.

try
        {               
            newStudent = new Student();
            newStudent.StudentName = "James007";
            
            ValidateStudent(newStudent);
        }
        catch(InvalidStudentNameException ex)
        {
            Console.WriteLine(ex.Message );
        }