Update on this problem.
It would appear that the culprit is Avast anti virus software. Avast itself works perfectly ok, however should it signal that an 'important update' requires to be downloaded, it would be advisable to check first just what the 'important update' is for. The last one again downloaded 'Chrome' and ,once again, all direct links to the forum via the forum tab were lost along with the direct link to Airliners via the individual photos. Result, another restore had to be performed.
Moral is to be careful regarding Chrome. It may not be a problem with everyone but it certainly is for me !