diff --git a/AVRsack/ASApplication.swift b/AVRsack/ASApplication.swift
index 28d8aa5..46fa2f6 100644
--- a/AVRsack/ASApplication.swift
+++ b/AVRsack/ASApplication.swift
@@ -56,13 +56,13 @@ class ASApplication: NSObject, NSApplicationDelegate, NSMenuDelegate {
     func applicationDidFinishLaunching(aNotification: NSNotification) {
         themeMenu.removeAllItems()
         for (index, theme) in enumerate(ACEThemeNames.humanThemeNames() as! [String]) {
-            let menuItem = themeMenu.addItemWithTitle(theme, action: "changeTheme:", keyEquivalent: "")
-            menuItem!.tag = index
+            let menuItem = themeMenu.addItemWithTitle(theme, action: "changeTheme:", keyEquivalent: "")!
+            menuItem.tag = index
         }
         keyboardMenu.removeAllItems()
         for (index, theme) in enumerate(ACEKeyboardHandlerNames.humanKeyboardHandlerNames() as! [String]) {
-            let menuItem = keyboardMenu.addItemWithTitle(theme, action: "changeKeyboardHandler:", keyEquivalent: "")
-            menuItem!.tag = index
+            let menuItem = keyboardMenu.addItemWithTitle(theme, action: "changeKeyboardHandler:", keyEquivalent: "")!
+            menuItem.tag = index
         }
     }
     func applicationShouldOpenUntitledFile(sender: NSApplication) -> Bool {
@@ -142,15 +142,17 @@ class ASApplication: NSObject, NSApplicationDelegate, NSMenuDelegate {
     }
     
     @IBAction func openSketch(item: NSMenuItem) {
-        let url = NSURL(fileURLWithPath: sketches[item.tag])!
-        let doc = NSDocumentController.sharedDocumentController() as! NSDocumentController
-        doc.openDocumentWithContentsOfURL(url, display: true) { (doc, alreadyOpen, error) -> Void in
+        if let url = NSURL(fileURLWithPath: sketches[item.tag]) {
+            let doc = NSDocumentController.sharedDocumentController() as! NSDocumentController
+            doc.openDocumentWithContentsOfURL(url, display: true) { (doc, alreadyOpen, error) -> Void in
+            }
         }
     }
     
     @IBAction func openExample(item: NSMenuItem) {
-        let url = NSURL(fileURLWithPath: examples[item.tag])!
-        openTemplate(url.URLByDeletingLastPathComponent!)
+        if let url = NSURL(fileURLWithPath: examples[item.tag]) {
+            openTemplate(url.URLByDeletingLastPathComponent!)
+        }
     }
 
     @IBAction func createSketch(AnyObject) {
diff --git a/AVRsack/ASBuilder.swift b/AVRsack/ASBuilder.swift
index 526a0f1..8b1aa70 100644
--- a/AVRsack/ASBuilder.swift
+++ b/AVRsack/ASBuilder.swift
@@ -56,6 +56,10 @@ class ASBuilder {
         let fileManager = NSFileManager.defaultManager()
         let libPath     = (ASLibraries.instance().directories as NSArray).componentsJoinedByString(":")
         var args        = [String]()
+        if ASHardware.instance().boards[board] == nil {
+            NSLog("Unable to find board %s\n", board);
+            return
+        }
         let boardProp   = ASHardware.instance().boards[board]!
         let library     = boardProp["library"]!
         var corePath    = library+"/cores/"+boardProp["build.core"]!
@@ -82,8 +86,8 @@ class ASBuilder {
         args.append("core="+boardProp["build.core"]!)
         args.append("libs="+libPath)
         args.append("core_path="+corePath)
-        if variantPath != nil {
-            args.append("variant_path="+variantPath!)
+        if let varPath = variantPath {
+            args.append("variant_path="+varPath)
         }
         args.append("usb_vid="+(boardProp["build.vid"] ?? "null"));
         args.append("usb_pid="+(boardProp["build.pid"] ?? "null"));
@@ -125,7 +129,11 @@ class ASBuilder {
             task!.standardOutput    = logOut
             task!.standardError     = logOut
         }
-        
+        if ASHardware.instance().boards[board] == nil {
+            NSLog("Unable to find board %s\n", board);
+            return
+        }
+
         let libPath         = (ASLibraries.instance().directories as NSArray).componentsJoinedByString(":")
         let boardProp       = ASHardware.instance().boards[board]!
         let progProp        = ASHardware.instance().programmers[programmer]
diff --git a/AVRsack/ASFileTree.swift b/AVRsack/ASFileTree.swift
index 49f612f..c124ddb 100644
--- a/AVRsack/ASFileTree.swift
+++ b/AVRsack/ASFileTree.swift
@@ -252,7 +252,7 @@ class ASFileTree : NSObject, NSOutlineViewDataSource {
     func addFileURL(url: NSURL, omitUnknown: Bool = true) {
         let type = ASFileType.guessForURL(url)
         if !omitUnknown || type != .Unknown {
-            root.children.append(ASFileItem(url: url.standardizedURL!, type: type))
+            root.children.append(ASFileItem(url: url.URLByStandardizingPath!, type: type))
         }
     }
     func setProjectURL(url: NSURL) {
diff --git a/AVRsack/ASProjDoc.swift b/AVRsack/ASProjDoc.swift
index 64967f3..911c0a4 100644
--- a/AVRsack/ASProjDoc.swift
+++ b/AVRsack/ASProjDoc.swift
@@ -222,7 +222,7 @@ class ASProjDoc: NSDocument, NSOutlineViewDelegate, NSMenuDelegate, NSOpenSavePa
  
     func updateLog(AnyObject?) {
         if let logNode = mainEditor as? ASLogNode {
-            let url = fileURL!.URLByDeletingLastPathComponent?.URLByAppendingPathComponent(logNode.path)
+            let url = fileURL?.URLByDeletingLastPathComponent?.URLByAppendingPathComponent(logNode.path)
             if url == nil {
                 return
             }