VST instruments not recognising controllers

I wonder if anyone can help or am I being stupid! :blush:
My midi/usb controller works in windows 10 and will control my stand-alone VST instruments outwith cubase (8.5 & 8).
In the past 3 weeks they have stopped controlling or being recognised by the VST instruments in Cubase, both cubase originals, padshop etc and third party (Arturia, Tone 2, IK Multi etc).
The midi devices are recognised, show up in my projects and I can record midi, notes, velocity, aftertouch, all changes etc etc (via midi or usb) by the controllers and this will then playback the VST instruments fine - I just can’t get to play a VST instrument within Cubase. :imp:

I’ve checked/unchecked midithru, reset midi, checked devices active etc to no avail.

Any help, suggestions much appreciated.

System: Windows 10, Cubase 8.5.30, EMU 1616M soundcard, Arturia Lab controller (USB), Emu command station (MIdi & Audio), TR8s (USB & Audio), Prophet 600(Midi & Audio), (Arturia, IK mutimedia VST’s)