Make your app user-friendly

1. Add “Your choice:”. When the program is waiting for the user input, you need to inform the user that the app isn’t processing smth, it is waiting for his/her choice. For instance, “Your choice: ...user's_input here...”
   
2. It isn’t obvious for the user what to input, the app expects the NAME of the file to be entered, not full/relative file path:
   
3. The same issue is with your “add” method:
   
   Let's consider the case: the user entered invalid data and received a message about an error. What should the user do next? Re-enter the data until it is valid, or choose the add option again and start from the beginning? You need to inform the user what step is expected from him/her at the particular moment
4. More about your “add” command:
   Let's consider the next case: the user enters an item, but makes a mistake in the last field and the app gets invalid data. It throws an error, but the process of adding an element is interrupted -> the user loses all previously entered data and must enter everything all over again. It is better to implement smth like this: if invalid data is entered, display a message about a mistake, and offer to enter this field again (for convenience, you can add an option to exit the process of adding a record)
5. Validation: not user-friendly message.
   
   By the way, it’s not a good idea to catch exceptions in Main.
6. Another test case: after launching the app the user decided to enter a record with an “add” option. After that he/she decided to read data from file. Guess what happened? The collection was overwritten with new records, that first added record was erased --> voilà! The user lost data.
7. Format the file properly (“write” option), not readable.
   
8. Don’t forget to add a message that a record with such id doesn’t exist for methods where it is needed + you should add messages about successful operations, we have already discussed it.
9. Seems that you have big problems with EDIT option:
   
   
10. Smth went wrong:
    
    Investigate the case:
    
    Exception here:
    

Tip:

I advise you to install StyleCop (open-source static code analysis tool) for this project. You need to get used to the recommended rules of code writing style in C#.