diff --git a/LiveContainerUI/LCUtils.m b/LiveContainerUI/LCUtils.m
index 0b7c521..293ed73 100644
--- a/LiveContainerUI/LCUtils.m
+++ b/LiveContainerUI/LCUtils.m
@@ -187,7 +187,17 @@ + (NSProgress *)signAppBundle:(NSURL *)path completionHandler:(void (^)(BOOL suc
     }
 
     ALTCertificate *cert = [[NSClassFromString(@"ALTCertificate") alloc] initWithP12Data:self.certificateData password:self.certificatePassword];
+    if (!cert) {
+        error = [NSError errorWithDomain:NSBundle.mainBundle.bundleIdentifier code:1 userInfo:@{NSLocalizedDescriptionKey: @"Failed to create ALTCertificate"}];
+        completionHandler(NO, error);
+        return nil;
+    }
     ALTProvisioningProfile *profile = [[NSClassFromString(@"ALTProvisioningProfile") alloc] initWithURL:profilePath];
+    if (!profile) {
+        error = [NSError errorWithDomain:NSBundle.mainBundle.bundleIdentifier code:2 userInfo:@{NSLocalizedDescriptionKey: @"Failed to create ALTProvisioningProfile"}];
+        completionHandler(NO, error);
+        return nil;
+    }
 
     ALTAccount *account = [NSClassFromString(@"ALTAccount") new];
     ALTTeam *team = [[NSClassFromString(@"ALTTeam") alloc] initWithName:@"" identifier:@"" /*profile.teamIdentifier*/ type:ALTTeamTypeUnknown account:account];