Please read this blog before reinstalling a previous version, otherwise, you might mistakenly uninstall the current version of Premiere Pro installed on your computer.
Here are instructions for how to reinstall a previous version of any Adobe Creative Cloud application: Download and install Creative Cloud apps
To reinstall any previous version of Premiere Pro, follow these steps:
5. Find Premiere Pro in the list and click on the Install drop-down.
6. Choose the previous version of Premiere Pro that you want to install on your computer.