Hi @shafeeqmhg
According to engineering there are breaking changes and features that are not supported from SDK 1.3.x with Couchbase Server 4.1. Unfortunately we don’t have a complete list of breaking changes.
I know there it’s not minor upgrade to change SDK 1.3.x to 2.x, but this is our recommended approach. With that said, you could try to run a few tests against CB 4.1 with SDK 1.3 and test if the features that you are using are supported.
Depending on your application setup one great benefit when using SDK 2.x is that it supports cross platform usage etc. you can create and read documents created from different plaforms: java, .net, etc.
I hope this helps.