We confirm this to be an unfortunate compatibility bug between version 3.0.1 and Server 6.1. We are now delivering an "hotfix" on the 3.0.1 version.

If you installed the iOS Client Library via CocoaPods, clean its cache to force it to download the hotfixed version. Run the following command:
  • pod cache clean Lightstreamer_iOS_Client

If it asks which version, choose the 3.0.1 version. If 3.0.1 version is listed more than one time, repeat the command.

Once the cache is clean, remove the "Pods" directory and run CocoaPods again on your project:
  • rm -Rf Pods; pod install


If you installed the iOS Client Library manually, just re-download the binary from the original link:

Then replace the framework in your project.

Let us know when the problem is fixed.