Sad to say it appears I was a bit hasty with my "assumption" that everything was fine !
After I registered msscript.ocx FARR started without any errors ... yupiii !
But ... while using it and installing new plugins I started to experience same Runtime Error as before.
When does this happen (these are examples of situations I encountered so far; there may be more): if i use Locate32 plugin and I left click on any result I get an odd error (does not crash FARR); if I hit down arrow or enter key then the big runtime error appears and FARR crashes.
Same thing is happening when using FarrMilk plugin (remember that FARR starts correctly and I am able to see the search results ... just can't use them).
The strange thing is that I am able to use plugins dependent on fscript.dll without problems, like Clock or TodoTXT; the runtime error is still related to fscript.dll as you will see in my small video recording (~800KB), although Locate32 plugin does not use fscript.dll I belive (and some searches are working normally !!!) ...
This is completly beyond my comprehension ...
I really hope you can figure this one out ! Maybe there are some more .ocx's or .dll's that need to be registered.