InvalidArgumet=Value of '0' crash

[anon8675309]

Describe the bug
Clicking Start/Edit/Configure when a ROM is not selected results in an unhandled exception.

To Reproduce
Steps to reproduce the behavior:

1. Start 86BoxManager
2. Add a ROM
3. Select the ROM
4. Click Edit
5. Click Apply
6. Click OK, at this point you are back at the main screen and the buttons such as "Edit", "Start", and "Configure" are enabled, but no ROM is selected
7. Click "Edit", "Start" or "Continue" button
8. Observe unhandled exception error

Expected behavior
As a user, after editing a ROM, I would expect it to still be selected. Alternatively, I would expect all of the buttons which will not work when a ROM is not selected to be disabled.

Screenshots

Environment (please complete the following information):

• Host OS: WIndows 10 version 2004
• 86Box 86Box-32-245af88d
• 86Box Manager Version 1.7.2

Additional context
n/a