I am trying to upgrade solidus_core to 3.1.5 (lates version till date) causing issue with solidus_braintree as this gem is deprecated on arrival of solidus_paypal_braintree gem.
But wondering if any easy to fix solutions available keeping solidus_braintree gem?
The solution would be to update the extension to support the new version of Solidus. If the upstream project isn't accepting changes, you can maintain support for new versions of Solidus in a fork.