Having installed Visual Studio 2017 Professional with the SQL Data Tools component I tried to open a SSIS package. This failed to load and was listed as incompatible and that the application wasn’t installed.
I ran the SQL Server Data Tools (SSDT) install and added the SQL Server Integration Services component to my existing Visual Studio installation. Unfortunately, it was still showing as incompatible and that the application wasn’t installed.
The resolution was to right click on the project and click reload. This reloaded the project files from disk and I was able to edit the package.