fix crash

cmd/gui/window/mainwindow/mainwindow.go

@@ -43,6 +43,14 @@ func Make(a fyne.App, d *data.Service) fyne.Window {
 	toolbar := widget.NewToolbar(
 		widget.NewToolbarAction(theme.FolderNewIcon(), func() {
 			folderSelection := dialog.NewFolderOpen(func(lu fyne.ListableURI, err error) {
+				if err != nil {
+					d := dialog.NewError(fmt.Errorf("failed to open window: %w", err), w)
+					d.Show()
+					return
+				}
+				if lu == nil {
+					return
+				}
 				confirmDialog := dialog.NewConfirm("Add", "Do you want to add and scan '"+lu.Path()+"'?", func(accepted bool) {
 					if !accepted {
 						return
@@ -55,22 +63,32 @@ func Make(a fyne.App, d *data.Service) fyne.Window {
 					go func() {
 						gameID, err := d.Add(name, lu.Path(), "")
 						if err != nil {
-							d := dialog.NewError(fmt.Errorf("failed to create metadata the directory: %w", err), w)
-							d.Show()
+							fyne.Do(func() {
+								d := dialog.NewError(fmt.Errorf("failed to create metadata the directory: %w", err), w)
+								d.Show()
+								loadingDialog.Hide()
+							})
 							return
 						}
 
 						_, err = d.Scan(gameID)
 						if err != nil {
-							d := dialog.NewError(fmt.Errorf("failed to scan the directory: %w", err), w)
-							d.Show()
+							fyne.Do(func() {
+								d := dialog.NewError(fmt.Errorf("failed to scan the directory: %w", err), w)
+								d.Show()
+								loadingDialog.Hide()
+							})
 							return
 						}
 
 						games, err = d.AllGames()
 						if err != nil {
-							d := dialog.NewError(fmt.Errorf("failed to load datastore: %w", err), w)
-							d.Show()
+							fyne.Do(func() {
+								d := dialog.NewError(fmt.Errorf("failed to load datastore: %w", err), w)
+								d.Show()
+								loadingDialog.Hide()
+							})
+							return
 						}
 
 						fyne.Do(func() {