If you open a HDR Light Studio project and you see unexpected red lights on your canvas and light list, this means that the referenced textures have not been found. This is probably because the project was created on another computer. The file paths are absolute, so the operating system user name is included in the path. Open the project on another computer and the preset textures are not found.
But this take 2 clicks to fix!
Go to the Project menu and select Manage File Links
In that panel press the Relink Presets button and the textures will be found in your installed presets.