Getting wp_error breaks

[ Moderator note: moved to How-to and Troubleshooting. ]

I have been using the following code to access WordPress errors; however, recently, this stopped working. It breaks any code following it and if submitting a form, leads to 500 page error. I have tried putting it in a try/catch, but the code somehow still breaks.

I use this to get the errors, which appears to work fine.

public static function GetErrors()
{
    static $wp_error;
    return isset($wp_error) ? $wp_error : ($wp_error = new WP_Error(null, null, null));
}

Then I use this to get the error codes, which is what breaks.

\MyNamespace\MyStaticClass::GetErrors() -> get_error_codes()