Originally Posted by skamalpreet
Hi Rich....the problem is that the problem manifested itself only a few days ago...before that it was fine...or maybe I just did not notice ...which might be a bit unlikely as I have been using lightroom for the past 2 years
That makes it rather likely that the note above about the colour space is the cause of the problem. Inadvertently you changed the export colour space to AdobeRGB or even ProPhotoRGB from sRBG. sRBG is what you need for computer screens.
The setting is in the Export screen under File Settings > Color Space.