This error may appear if you are using a 3rd party plugin with your AppController file separate from Helpshift, such as AppsFlyer, which results in there being 2 different app controllers present in the same project.

To solve this error, you should implement one single appController which receives all relevant code from both of the other app controllers. This common appController should be the only one present in the project, and the other appControllers should be removed.