Harden game loading, try to prevent crashes & storing invalid game file

names in the settings file.

RandoTracker/Form1.cs

@@ -107,6 +107,12 @@ private void Form1_Load(object sender, EventArgs e)
  // ignore error
  }
 
+ if (string.IsNullOrWhiteSpace(gameFile))
+ {
+ // Load something at least
+ gameFile = Path.Combine(GetExecutingDirectory(), "sml2.xml");
+ }
+
  this.Left = 200;
  this.Top = 200;
 
@@ -191,6 +197,7 @@ private void Form1_Load(object sender, EventArgs e)
  catch (Exception ex)
  {
  MessageBox.Show($"Error loading {gameFile}. {ex.Message}", "Error Loading Game");
+ gameFile = string.Empty;
  return;
  }
 
@@ -345,7 +352,16 @@ private FontFamily loadFont(string fontName)
 
  private void loadGame()
  {
- if (initialLoad) return;
+ if (initialLoad)
+ {
+ return;
+ }
+
+ if (string.IsNullOrWhiteSpace(gameFile))
+ {
+ return;
+ }
+
  for (int i = 0; i < 4; i++)
  {
  if (lblPlayers[i] != null)
@@ -423,7 +439,7 @@ private void loadGame()
 
  if (game == null)
  {
- MessageBox.Show("Unable to find root game tag", "Required Tag");
+ MessageBox.Show($"Unable to find root game tag for {gameFile}", "Required Tag");
  return;
  }
 
@@ -1678,7 +1694,17 @@ private void reloadLayout()
  }
  else
  {
- loadGame();
+ try
+ {
+ loadGame();
+ }
+ catch (Exception ex)
+ {
+ MessageBox.Show($"Failed to reload {gameFile}. {ex.Message}", "Layout Load Error");
+ gameFile = string.Empty;
+ return;
+ }
+
  serverSendBytes(0xf4, Encoding.UTF8.GetBytes(Path.GetFileNameWithoutExtension(gameFile)));
  }
  }