Installed Transit Package Handler in 03/2019 not working anylonger.

I am using Studio 2017 (SR 1 - 14.1.10015.44620) on Win 8.1. In March 2019 I downloaded and installed the Transit Package Handler. After some attempts with the settings, it finally worked and I could translate the package. Now, two months later, when I need to translate another Transit package, the file extension PPF is no longer available in the file type list, which means I can not open the package. Downloading the app again is possible, but it's not possible to install again as the system informs me there is a previous version. I can not find and remove the previous version. Any idea how to get out of this Catch 22? Thanks a lot in advance.