The problem I am reporting is only valid for F15 in FC3. If I chose any other of the available aircraft, the missions works fine and as expected.
After having started 1 of the 2 preinstalled missions for F15, no keyboard inputs are accepted. It is not a complete game crash - you can hear communication and see other vehicles moving on the ground, but with no keyboard inputs accepted the only way out is Ctrl,Alt,Del.
The problem started with the new version of DCS World, so the problem cause could possibly be related to this revision. Has anybody else experienced the same behaviour?