You may try the following to uninstall RMADFE from the server:
1- Locate your old Recovery Manager for AD Forest Edition installation media.
2- Right-Click autorun.exe and click on Run as administrator.
3- Click Setup, then click Install and click next.
4- Click on Remove and go through the the wizard until the removal process is complete.
If the above fails, then download Microsoft Troubleshooter from the following link and try to remove the product using that MS tool:https://support.microsoft.com/en-us/topic/fix-problems-that-block-programs-from-being-installed-or-removed-cca7d1b6-65a9-3d98-426b-e9f927e1eb4d