This plugin is being installed with a uninstall ID of {}_is1

This is because the UUID_APP is not defined during building of the iss file. Here is the line from installer-Windows.iss.in:

AppId={{@UUID_APP@}

This causes a problem when OBS users install the DistroAV plugin. When that plugin is installed, it uninstalls the {}_is1 plugin because that plugin had the same bug (not using a unique ID for the app) in a previous version.

Since the UUID is in the buildspec.json, the simplest change is to add these lines to the bootstrap.cmake file:

string(JSON _windowsAppUUID GET ${buildspec} uuids windowsApp)
set(UUID_APP ${_windowsAppUUID})

The more correct, but much more extensive, change, is to move up to the new plugin template for OBS Studio.

I can make the simple PR as shown above if no one has time.