This is fairly self-explanatory.
When the mod is installed (specifically when the2 api and dll files are placed in bin)
the hammer editor does not open. When removing the files from your game, it works again.
likely cannot be fixed. d3d9.dll replaces the game's (and hammer's) DirectX and replaces it to use Vulkan instead. hammer probably can't load under vulkan.
This is fairly self-explanatory. When the mod is installed (specifically when the2 api and dll files are placed in bin) the hammer editor does not open. When removing the files from your game, it works again.