Changing return type of start method in batch class in managed package

Question

We are developing a managed package and I am working on a batch class which has been packaged in dev enviroment and our app is deployed to our testing org as well.

Currently return type of start method is List < sObject > and now we need to change it to Iterable < WrapperClass >, will it cause any problem while upgrading package in that testing org.

Answer 1

global methods cannot have the number of parameters, the type of parameters, the return type, the access level, or the name of method altered after a successful Released version upload. In the future, consider making your methods public unless they need to be accessible outside the Managed Package. It is legal to make a global class with public methods for implemented interfaces to avoid this problem. Unfortunately, it's too late to change it now, unless you're able to somehow rollback to a Beta package, which involves uninstalling the any later package version from all orgs where the package is installed.