diff --git a/Signal/SignalUBSan.supp b/Signal/SignalUBSan.supp
index 043c00979..048ffabf6 100644
--- a/Signal/SignalUBSan.supp
+++ b/Signal/SignalUBSan.supp
@@ -30,3 +30,5 @@ shift-base:fe_tobytes.c
 shift-exponent:fe_tobytes.c
 shift-base:sc_reduce.c
 shift-exponent:sc_reduce.c
+shift-base:sc_muladd.c
+shift-exponent:sc_muladd.c
diff --git a/SignalMessaging/contacts/SelectRecipientViewController.m b/SignalMessaging/contacts/SelectRecipientViewController.m
index 506f8e44e..8104548bf 100644
--- a/SignalMessaging/contacts/SelectRecipientViewController.m
+++ b/SignalMessaging/contacts/SelectRecipientViewController.m
@@ -319,12 +319,22 @@ NSString *const kSelectRecipientViewControllerCellIdentifier = @"kSelectRecipien
                           [[ContactsUpdater sharedUpdater] lookupIdentifiers:possiblePhoneNumbers
                               success:^(NSArray<SignalRecipient *> *recipients) {
                                   OWSAssertIsOnMainThread();
-                                  OWSAssert(recipients.count > 0);
-
                                   if (modalActivityIndicator.wasCancelled) {
                                       return;
                                   }
 
+                                  if (recipients.count == 0) {
+                                      [modalActivityIndicator
+                                          dismissViewControllerAnimated:NO
+                                                             completion:^{
+                                                                 NSError *error
+                                                                     = OWSErrorMakeNoSuchSignalRecipientError();
+                                                                 [OWSAlerts showErrorAlertWithMessage:
+                                                                                error.localizedDescription];
+                                                             }];
+                                      return;
+                                  }
+
                                   NSString *recipientId = recipients[0].uniqueId;
                                   [modalActivityIndicator
                                       dismissViewControllerAnimated:NO
diff --git a/SignalServiceKit/src/Contacts/ContactsUpdater.h b/SignalServiceKit/src/Contacts/ContactsUpdater.h
index 714f9c04b..732b2c5c4 100644
--- a/SignalServiceKit/src/Contacts/ContactsUpdater.h
+++ b/SignalServiceKit/src/Contacts/ContactsUpdater.h
@@ -10,15 +10,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 + (instancetype)sharedUpdater;
 
-// This asynchronously tries to verify whether or not a contact id
-// corresponds to a service account.
-//
-// The failure callback is invoked if the lookup fails _or_ if the
-// contact id doesn't correspond to an account.
-- (void)lookupIdentifier:(NSString *)identifier
-                 success:(void (^)(SignalRecipient *recipient))success
-                 failure:(void (^)(NSError *error))failure;
-
 // This asynchronously tries to verify whether or not a group of possible
 // contact ids correspond to service accounts.
 //
diff --git a/SignalServiceKit/src/Contacts/ContactsUpdater.m b/SignalServiceKit/src/Contacts/ContactsUpdater.m
index b2a01eef7..22a65c45a 100644
--- a/SignalServiceKit/src/Contacts/ContactsUpdater.m
+++ b/SignalServiceKit/src/Contacts/ContactsUpdater.m
@@ -20,7 +20,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
-
 @implementation ContactsUpdater
 
 + (instancetype)sharedUpdater {
@@ -48,34 +47,6 @@ NS_ASSUME_NONNULL_BEGIN
     return self;
 }
 
-- (void)lookupIdentifier:(NSString *)recipientId
-                 success:(void (^)(SignalRecipient *recipient))success
-                 failure:(void (^)(NSError *error))failure
-{
-    OWSAssert(recipientId.length > 0);
-    
-    // This should never happen according to nullability annotations... but IIRC it does. =/
-    if (!recipientId) {
-        OWSFail(@"%@ Cannot lookup nil identifier", self.logTag);
-        failure(OWSErrorWithCodeDescription(OWSErrorCodeInvalidMethodParameters, @"Cannot lookup nil identifier"));
-        return;
-    }
-    
-    NSSet *recipiendIds = [NSSet setWithObject:recipientId];
-    [self contactIntersectionWithSet:recipiendIds
-                             success:^(NSSet<SignalRecipient *> *recipients) {
-                                 if (recipients.count > 0) {
-                                     OWSAssert(recipients.count == 1);
-                                     
-                                     SignalRecipient *recipient = recipients.allObjects.firstObject;
-                                     success(recipient);
-                                 } else {
-                                     failure(OWSErrorMakeNoSuchSignalRecipientError());
-                                 }
-                             }
-                             failure:failure];
-}
-
 - (void)lookupIdentifiers:(NSArray<NSString *> *)identifiers
                  success:(void (^)(NSArray<SignalRecipient *> *recipients))success
                  failure:(void (^)(NSError *error))failure
@@ -88,11 +59,11 @@ NS_ASSUME_NONNULL_BEGIN
 
     [self contactIntersectionWithSet:[NSSet setWithArray:identifiers]
                              success:^(NSSet<SignalRecipient *> *recipients) {
-                                 if (recipients.count > 0) {
-                                     success(recipients.allObjects);
-                                 } else {
-                                     failure(OWSErrorMakeNoSuchSignalRecipientError());
+                                 if (recipients.count == 0) {
+                                     DDLogInfo(
+                                         @"%@ in %s no contacts are Signal users", self.logTag, __PRETTY_FUNCTION__);
                                  }
+                                 success(recipients.allObjects);
                              }
                              failure:failure];
 }