Hi. I am not new to FSX but am new to this forum. I have been running FSX acceleration on my computer for some while, and apart from a few small glitches all worked well.. Unfortunately, originally I had a French version of Windows 7 64 bit. I changed to an English version of Win 7 64 and then p[roceeded to reinstall FSX and all the add ons that I had accumulated. Everything appeared ok until one day while flying close to Dinard in Brittany I saw what appeared to be a curtain or wall of scenery reaching up from the ground to the heavens. It appeared to travel with me and increased in length in front but decreased behind as I travelled. As I was flying IFR at the time I resolved to examine this lated. I did this but could find no apparent reason. I unistalled then reinstalled FSX accleration and checked the scenery again without any add ons. The scenery was perfect. I then reinstalled my add ons, (Iknow I should have checked after each add on installation, but didn't). Of course the problem was back. If you try to fly through then wall you suddenly find yourself at over 50,000 feet, which in a light aircraft causes a few problems. The line seems to run almost exactly north to south, with gaps where there is water or a road running through at ground level. You can fly through the gaps with no adverse affect. It starts at the edge of the sea near St. malo and travels due south towards Rennes. I am not sure iof it reaches Rennes or goes on south from there as I got rather upset by it. I thought one of the causes might have been a crosswind runway that I put in at Bordeaux airport using ADE9X. I have enclosed a screenshot of the fault. I have tried downloading and installing a new terrain mesh for Europe but this has had no effect at all. I would be most grateful of any suggestions (other than reinstalling the whole lot again, because that is the only thing I can think of anyway).