Young birthdates seem to make UserState stop functioning when filled first

## Expected Behavior

Allow the user to continue through to the end regardless of their birthdate as long as they fix it to be in an allowed range.

## Current Behavior

When the user immediately sets the birthdate to 12/28/1992 and uses the example sample20.xml file downloadable from the main page, the Detailed Calculator seems to stop working until the UserState is cleared out.

## Possible Solution

- We should check into the logic that shows the warning for young people (<60yo) on the birthday page. It could be that the logic that is setting the calculator at that stage is throwing an error and interrupting future operation or otherwise affecting the UserState.

## Steps to Reproduce

1. Go to ssacalculator.org and continue to second page
2. Setting Birthdate to 12/28/1992 on results page (Detailed Calc)
3. Go to second page and upload the Sample20.xml file from the start page.
4. Press no on the third page about whether "earnings shown"
5. Continue to results and observe an error.
6. Go back to initial background page and try to fix birthdate to normal retiree range.
7. go to results page and observe the error regardless of new birthdate.

## Context (Environment)

Discovered in Chrome on Windows and partly replicated on Chrome on macOS.

## Detailed Description

-TBD

## Possible Implementation
- TBD