Yes. Thank you for uploading stuff. It shows that you have been working on the overall project. There is no way I can rearchitect your project for you. I have my own work I need to do. But I will give you a few pieces of advice.
1. You are abusing local variables in your code. There are places where you are reading and writing to the terminal and local variables at roughly the same time which gives you a race condition. You have no control as to what value gets used or stored because you have no control over the order of the operations.
2. There is a lot of intertwined code where something happening before this, and after that, which happens before something else. And the only way it all wires up is through feedback nodes. So it is very confusing as to whether a particular structure is working on data from the currenlt loop's iteration, or a previous loop iteration.
3. It is good to see you have a flowchart, but it needs more detail. It is really more of a block diagram then a flowchart. It needs more flow. You need some detail as to what happens in each block. "Add User", what steps does that entail? Likewise "Scanning" and "Search".
4. A lot of controls in your block diagram don't show up on your front panel. Are they hidden?
5. It seems like you are reading and writing to the same couple of text files alot. You shouldn't need to read from the same file multiple times in a loop iteration.
Your architecture needs to be more of an event driven state machine. You have an event structure, but some of those other buttons need to be a part of the event structure. So when you press Add User, assuming you are in a state that would allow that, would go through a series of steps.
Your state machine would consist of an Idle state, Login, Wait for Scan, Logout. Other states would be to read from and write to the file.
