I looked in to this bug a bit and error 998 is returned when the DLL being loaded crashes. So for some reason the plugins are crashing when they are loading. The only thing to do is to debug it, but it works for me and everyone else, so I don't know what to do :S
The only thing I can think of is to completely uninstall, delete all Construct related files, delete the folder HKEY_CURRENT_USER\Software\Construct from the registry (in regedit), and reinstall Construct again, installing both the CRT and DirectX update. There's an outside chance installing this update might help as well.