RhinoScript.rhp not loading

since a few days i get the following error message when starting rhino:

when then trying to use my plugin, rhino says:

what can i to to fix this? it worked flawlessly till last week …

Hi - please try to repair your Rhino 6 installation (Windows Control Panel > Programs and Features > Rhino 6 > Repair)

meanwhile rhino did a self-repair ; )
lets see if the error returns.