[Bug]: Forks are fail when objects get changes (number OR name of the properties of an object)

[golnar-m]

Summary of Bug

We have an issue. We've stored some objects in the kvstore and in our testnet some clients started to use our blockchain.

Now we changed 2 of the objects, for one of them we increased the number of the properties and the second object we changed the name of a property.

Now, we have a problem with already registered clients, we can not Get Client Object after these changes. Because they are forked from the previous client object.

Version

v0.45.5

Steps to Reproduce

1- Pull the new code
2- Build the binary
3- The new binary will be replaced with the old one
4- And when we do soarchaind start again the new binary will run with the already saved data which is a "hard fork" basically.
5-Because object is changed (for example the name of the object changed from index ---> pubkey ) we got error for fetching the data.

[facundomedica]

I'm not 100% sure I understood the problem here, but it sounds like you are missing a migration.
Every time you do a state breaking change, you must do a migration in which you basically go through your previous version's data and re-write it in the new version format. See here https://docs.cosmos.network/main/core/upgrade

If this is not what you are looking for, please add more details (like actual examples of the objects you've changed and the error you are getting)

[golnar-m]

@facundomedica Thank you. That was the solution.