diff --git a/IdentityCore/src/oauth2/aad_v2/MSIDAADV2Oauth2Factory.m b/IdentityCore/src/oauth2/aad_v2/MSIDAADV2Oauth2Factory.m
index c8f0056fc..4b08f59cd 100644
--- a/IdentityCore/src/oauth2/aad_v2/MSIDAADV2Oauth2Factory.m
+++ b/IdentityCore/src/oauth2/aad_v2/MSIDAADV2Oauth2Factory.m
@@ -88,7 +88,7 @@ - (BOOL)verifyResponse:(MSIDAADV2TokenResponse *)response
 
     if (!result)
     {
-        if (response.error)
+        if (response.error && error)
         {
             *error = MSIDCreateError(MSIDOAuthErrorDomain,
                                      response.oauthErrorCode,
diff --git a/IdentityCore/src/util/NSString+MSIDExtensions.m b/IdentityCore/src/util/NSString+MSIDExtensions.m
index 4331ec6aa..6614c39d4 100644
--- a/IdentityCore/src/util/NSString+MSIDExtensions.m
+++ b/IdentityCore/src/util/NSString+MSIDExtensions.m
@@ -162,7 +162,7 @@ + (NSString *)msidHexStringFromData:(NSData *)data
     
     if (!charBytes) return nil;
     NSUInteger dataLength = data.length;
-    NSMutableString *result = [NSMutableString stringWithCapacity:dataLength];
+    NSMutableString *result = [NSMutableString stringWithCapacity:dataLength*2];
     
     for (int i = 0; i < dataLength; i++)
     {
diff --git a/IdentityCore/src/webview/embeddedWebview/MSIDOAuth2EmbeddedWebviewController.m b/IdentityCore/src/webview/embeddedWebview/MSIDOAuth2EmbeddedWebviewController.m
index 66166d1d9..539765bc9 100644
--- a/IdentityCore/src/webview/embeddedWebview/MSIDOAuth2EmbeddedWebviewController.m
+++ b/IdentityCore/src/webview/embeddedWebview/MSIDOAuth2EmbeddedWebviewController.m
@@ -272,6 +272,11 @@ - (void)webView:(WKWebView *)webView didFailNavigation:(null_unspecified WKNavig
     [self webAuthFailWithError:error];
 }
 
+- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation withError:(NSError *)error
+{
+    [self webAuthFailWithError:error];
+}
+
 - (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(ChallengeCompletionHandler)completionHandler
 {
     NSString *authMethod = [challenge.protectionSpace.authenticationMethod lowercaseString];
diff --git a/IdentityCore/src/webview/embeddedWebview/ui/ios/MSIDWebviewUIController.m b/IdentityCore/src/webview/embeddedWebview/ui/ios/MSIDWebviewUIController.m
index a2ba9fd91..b0aa1503f 100644
--- a/IdentityCore/src/webview/embeddedWebview/ui/ios/MSIDWebviewUIController.m
+++ b/IdentityCore/src/webview/embeddedWebview/ui/ios/MSIDWebviewUIController.m
@@ -27,6 +27,8 @@
 #import "UIApplication+MSIDExtensions.h"
 #import "MSIDAppExtensionUtil.h"
 
+static WKWebViewConfiguration *s_webConfig;
+
 @interface MSIDWebviewUIController ( )
 {
     UIActivityIndicatorView *_loadingIndicator;
@@ -40,6 +42,14 @@ @interface MSIDWebviewUIController ( )
 
 @implementation MSIDWebviewUIController
 
++ (void)initialize
+{
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        s_webConfig = [WKWebViewConfiguration new];
+    });
+}
+
 - (id)initWithContext:(id<MSIDRequestContext>)context
 {
     self = [super init];
@@ -86,8 +96,7 @@ - (BOOL)loadView:(NSError **)error;
     [rootView setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight];
     
     // Prepare the WKWebView
-    WKWebViewConfiguration *webConfiguration = [WKWebViewConfiguration new];
-    WKWebView *webView = [[WKWebView alloc] initWithFrame:rootView.frame configuration:webConfiguration];
+    WKWebView *webView = [[WKWebView alloc] initWithFrame:rootView.frame configuration:s_webConfig];
     [webView setAccessibilityIdentifier:@"MSID_SIGN_IN_WEBVIEW"];
     
     // Customize the UI
diff --git a/IdentityCore/src/webview/embeddedWebview/ui/mac/MSIDCertificateChooser.m b/IdentityCore/src/webview/embeddedWebview/ui/mac/MSIDCertificateChooser.m
index 6b737fc2c..d0f6f2d91 100644
--- a/IdentityCore/src/webview/embeddedWebview/ui/mac/MSIDCertificateChooser.m
+++ b/IdentityCore/src/webview/embeddedWebview/ui/mac/MSIDCertificateChooser.m
@@ -23,6 +23,7 @@
 
 #import <SecurityInterface/SFChooseIdentityPanel.h>
 #import "MSIDCertificateChooser.h"
+#import <MSIDNotifications.h>
 
 @implementation MSIDCertificateChooserHelper
 {
@@ -61,7 +62,7 @@ - (void)beginSheet:(NSArray *)identities
                      identities:identities
                         message:message];
     
-    //[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(webAuthDidFail:) name:ADWebAuthDidFailNotification object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(webAuthDidFail:) name:MSIDNotifications.webAuthDidFailNotificationName object:nil];
 }
 
 - (void)showCertSelectionSheet:(NSArray *)identities
@@ -87,10 +88,9 @@ - (void)sheetDidEnd:(__unused NSWindow *)window
     }
     
     SecIdentityRef identity = _panel.identity;
-    _panel = nil;
     _completionHandler(identity);
     _completionHandler = nil;
-    //[[NSNotificationCenter defaultCenter] removeObserver:self name:ADWebAuthDidFailNotification object:nil];
+    [[NSNotificationCenter defaultCenter] removeObserver:self name:MSIDNotifications.webAuthDidFailNotificationName object:nil];
 }
 
 - (void)webAuthDidFail:(__unused NSNotification *)aNotification
diff --git a/IdentityCore/src/webview/embeddedWebview/ui/mac/MSIDWebviewUIController.m b/IdentityCore/src/webview/embeddedWebview/ui/mac/MSIDWebviewUIController.m
index e1520dc32..2f703fc7e 100644
--- a/IdentityCore/src/webview/embeddedWebview/ui/mac/MSIDWebviewUIController.m
+++ b/IdentityCore/src/webview/embeddedWebview/ui/mac/MSIDWebviewUIController.m
@@ -28,6 +28,8 @@
 #define DEFAULT_WINDOW_WIDTH 420
 #define DEFAULT_WINDOW_HEIGHT 650
 
+static WKWebViewConfiguration *s_webConfig;
+
 @interface MSIDWebviewUIController ( ) <NSWindowDelegate>
 {
     NSProgressIndicator *_loadingIndicator;
@@ -37,6 +39,14 @@ @interface MSIDWebviewUIController ( ) <NSWindowDelegate>
 
 @implementation MSIDWebviewUIController
 
++ (void)initialize
+{
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        s_webConfig = [WKWebViewConfiguration new];
+    });
+}
+
 - (id)initWithContext:(id<MSIDRequestContext>)context
 {
     self = [super init];
@@ -60,8 +70,7 @@ - (BOOL)loadView:(NSError **)error
     NSView *rootView = window.contentView;
     
     // Prepare the WKWebView
-    WKWebViewConfiguration *webConfiguration = [WKWebViewConfiguration new];
-    WKWebView *webView = [[WKWebView alloc] initWithFrame:rootView.frame configuration:webConfiguration];
+    WKWebView *webView = [[WKWebView alloc] initWithFrame:rootView.frame configuration:s_webConfig];
     [webView setAccessibilityIdentifier:@"MSID_SIGN_IN_WEBVIEW"];
     
     // Customize the UI
diff --git a/IdentityCore/src/webview/systemWebview/ios/MSIDAuthenticationSession.m b/IdentityCore/src/webview/systemWebview/ios/MSIDAuthenticationSession.m
index dcd6e7ef0..2913dab7b 100644
--- a/IdentityCore/src/webview/systemWebview/ios/MSIDAuthenticationSession.m
+++ b/IdentityCore/src/webview/systemWebview/ios/MSIDAuthenticationSession.m
@@ -67,6 +67,7 @@ - (instancetype)initWithURL:(NSURL *)url
     {
         _startURL = url;
         _context = context;
+        _callbackURLScheme = callbackURLScheme;
     }
     
     return self;
diff --git a/IdentityCore/src/workplacejoin/mac/MSIDWorkPlaceJoinUtil.m b/IdentityCore/src/workplacejoin/mac/MSIDWorkPlaceJoinUtil.m
index 7fbf70fe1..0b98b752f 100644
--- a/IdentityCore/src/workplacejoin/mac/MSIDWorkPlaceJoinUtil.m
+++ b/IdentityCore/src/workplacejoin/mac/MSIDWorkPlaceJoinUtil.m
@@ -135,7 +135,7 @@ + (MSIDRegistrationInformation *)getRegistrationInformation:(id<MSIDRequestConte
 }
 
 
-+ (void)copyCertificate:(SecCertificateRef __nullable * __nonnull)certificate
++ (BOOL)copyCertificate:(SecCertificateRef __nullable * __nonnull)certificate
                identity:(SecIdentityRef __nullable * __nonnull)identity
                  issuer:(NSString * __nullable * __nonnull)issuer
                 context:(id<MSIDRequestContext>)context
@@ -170,7 +170,7 @@ + (void)copyCertificate:(SecCertificateRef __nullable * __nonnull)certificate
     // If there's no certificate in the keychain, adError won't be set since this isn't an error condition.
     if (!*certificate)
     {
-        return;
+        return NO;
     }
     
     // In OS X the shared access group cannot be set, so the search needs to be more
@@ -199,7 +199,7 @@ + (void)copyCertificate:(SecCertificateRef __nullable * __nonnull)certificate
     
     CFRelease(result);
     
-    return;
+    return YES;
     
 _error:
     
@@ -216,6 +216,8 @@ + (void)copyCertificate:(SecCertificateRef __nullable * __nonnull)certificate
     *certificate = nil;
     
     *issuer = nil;
+    
+    return NO;
 }