Purpose

There is lot of mix custom screen scheme associate with the project and would like to reset the project issue type screen scheme to the default one.

Solution

1. Go to Projects > Choose a project > Project Settings > Screens (tab) > Actions > select "Use a Different Scheme" > Default Issue Type Screen Scheme.
2. However, there is a limitation in JIRA where you can't do a bulk reset for all the projects. (Feature Request: JRA-41849 - Getting issue details... STATUS )