Thanks for getting back to me. I got assistance this morning using telephone /remote support from George.
When trying to edit any midi/Instrument tracks, Cubase stopped responding and had to be removed using Task Manager. Midi tracks could be created and played prior to this.
On PC, Start/Computer/OS(C:)/Users/Name/AppData/Roaming/Steinberg. Make new folder “Cubase Old Preferences” and place all earlier instances of Cubase files inside.
Restart Cubase and reorganise preferences.
I also had issues with the Echo Layla 3G settings - it lost the device ports to channels 1 & 2. I Drivers were checked and after a couple of restarts to the PC they reappeared.
Thank you again for following this up and special thanks to George