If you are moving from a newer version to an older one, it is best to perform a full uninstall. Residual files from a newer build can cause the older build to crash on startup. Key Milestone Versions
If you aren't sure which "old" version to pick, here are the highlights:
Upgrading your software in the middle of a major edit is a cardinal sin in post-production. If a project was built in version 17, opening it in 18 can sometimes cause plugin errors or timeline glitches.
Sometimes a macOS or Windows update breaks a specific version of Resolve. Reverting to an older build that matches your current OS is a common troubleshooting step. How to Download Official Legacy Versions
