I would like to followup on my 20 April message re how to apply the hotfix. I have been out of town since then and just got back to dealing with this problem. I tried making the hotfix and apparently it is not "taking" because I still get the fatal error message and Prepar3d closes. I first tried highlighting the hotfix files after extracting them and saving to my documents library, and then moving them directly to the Prepar3d folder in my documents library. The files seemed to move OK, but I did not get the "do I want to replace" message. Got the fatal error message after this attempt. I then tried the temporary desktop folder approach (placed the extracted hot fix files in it). I then moved the hotfix files over to the Prepar3d folder. I got a window that said moving 66 files. But, again I did not get the "do I want to replace " message and again when I tried to save a flight plan, got the fatal error message and Prepar3d closed. Apparently, I'm not doing something correct. I'm a software illiterate so this process is like flying blind. Any idea what I'm doing wrong or not doing correct? I am concerned that I may be screwing up my Prepar3d with all this fumbling around.